Giant Hippos (Who May or May Not Be Hungry)




Introduction: Giant Hippos (Who May or May Not Be Hungry)

About: Love to cook. Love to eat. Love to make stuff -- usually to help me cook or eat.

The hippos are coming. And they're hungry. Very hungry. You might even say, hungry hungry...

So you want to build a giant hippo head? It's OK to admit. You're amongst friends.

No, not a hippo? Maybe a giant dog head? Or giraffe. Or lion. Or Mt. Rushmore. Or maybe you want to build a temple filled with giant versions of your own head. No judging here. You're in the right place. Let's build together.

I made these for a fun side-game to be played at an ultimate frisbee tournament out of town (Seattle). A giant version of Hungry Hungry Hippos. The design had to be simple enough for us to fly into town, hit Home Depot, bring everything to the fields, and assemble with very few tools. That meant... PVC. Also known as Tinker Toys for adults.

This design is easily modified for whatever you need. Perfect for a festival, a parade, school fair, or just because. Again, we won't judge.


A crucial step in any good design process is building a scale model. Proof of concept. Made with pipe cleaners, where 1 inch = 1 foot. You don't have to do this. I'm just including it because I think it's pretty darned cute.



Raw materials (shopping list). Designed for the least amount of waste. This is for building ONE HIPPO. To build four, scale up.


  • (Qty: 2) 10' x 3/4" PVC Schedule 40 Plain End Pipe
  • (Qty: 1) 10' x 1/2" PVC Schedule 40 Plain End Pipe (white)
  • (Qty: 4) 10' x 1/2" PVC Schedule 40 Conduit (gray) LINK

Why use some PVC conduit (gray colored) instead of just using all PVC plumbing pipes (white)? Because conduit is more flexible -- easier to curve. Note that conduit usually has a bell end on one end.


Buy from or Home Depot

  • (Qty: 4) 3/4" 3-way PVC Elbow Fitting LINK
  • (Qty: 8) 3/4" PVC Tee Fitting LINK
  • (Qty: 4) 3/4 in. x 1/2 in. Schedule 40 PVC Reducer Bushing LINK (this is an adapter that goes from 1/2" female to 3/4" male)


  • (Qty: 3) 54in x 108in Plastic Table Cover (get from a party store - multiple colors)


  • Ratcheting PVC Cutter
  • Drill (or Dremel)
  • 24 Zip-ties
  • Clear Packing Tape
  • Duct Tape

Step 3: PIECES

Cut the PVC. A ratcheting PVC cutter makes quick work of this. Or you could use a saw. The nice thing about Home Depot is that you can make all your cuts there.

Cut the 10' x 3/4" PVC Pipes into

  • (2) 4' lengths
  • (4) 2' 6" lengths
  • (2) 6" lengths

Cut the 10' x 1/2" PVC Pipe into

  • (2) 4' 2" lengths
  • (1) 3' 10" length

Cut two of the 10' x 1/2" PVC Conduits into

  • (2) 7' lengths [save the remainders that have the bell ends]

For the other two 10' x 1/2" PVC Conduits,

  • just cut off the bell (socket) end so you have 10' lengths.


Now it's time to have some Tinker Toy fun. You'll start by assembling the rectangular base out of 3/4" PVC Pipe. Assemble according to the attached diagrams.

The 3-way Elbows are the corners, and the Tees connect along the long sides. After you've built the rectangular base, insert a bushing reducer into the top of each of the fittings. This will allow you to connect the 1/2" PVC Conduits.

Here's the Sketchup file (not necessary but gives you more detail).


A very important step. So important, that it has two exclamation points!!

Before you do anything else, you need to secure the frame you just made. When you get to the next step of bending/curving long pieces of PVC, you're entering dangerous territory. Oh yeah, probably a good time for a disclaimer here. Be safe.

If you're thinking, "Oh, it's just plastic, how dangerous could that be?" Go ahead and do a search on this site for PVC crossbows.

Now, you COULD use PVC solvent cement. That stuff works. But speed is an issue (no waiting around for it to dry), and the pieces will be under tension, so we need it to be instant. You could drill a hole and drive a screw into each connection, but an easier way (especially if you're in a field) is to first duct tape around each connection. Then drill a hole in each connection and run a zip-tie through and zip it. Now you've got a secure frame. Now move onto the dangerous step...


OK, not really that dangerous. But be careful anyway. Have a friend help you. You'll be using 1/2" PVC Conduit. These are gray, as opposed to the normal white PVC Pipes. The difference? PVC Conduit is used as tubing to house electrical wires. It's meant to be flexible. White PVC Pipes, on the other hand, are used for plumbing. We're going with Conduit because it's easier to bend.

Start with the 10' long back hoops. Connect according the diagrams. Careful when bending and insert fully into the fittings. Make sure everything is completely connected and tight. A friend would be nice here. But if you don't have one, well... still not judging.

Duct tape the connections immediately as you make them, then drill and zip-tie those as well.

Then do the 7' long front hoops. These will be a little harder to bend, but you got this. Just be careful. And don't stand with your head right in the line of fire should the Conduit pop out of its socket. Warn your friend too. Unless you don't really like him/her.

Duct tape, drill, and zip-tie.

Then have your friend get you a frosty beverage.


Now take the 1/2" PVC (white) pipe pieces. These will be crossbar supports. No fittings/connectors here. You're just gonna duct tape these.

Take one of the 4' 2" lengths and duct tape it between the front hoops about one foot off the ground. Why 4' 2"? Because the width of the hippo frame is 4' plus an inch on either side for the corner fittings. Make sure to place it on the back side of the hoops so that it doesn't protrude. If it were on the front, it would be a bulge when you put the skin on. See diagram.

Take the other 4' 2" length and duct tape it between the front of the back hoops. Yes, this time, it's placed in front, at the same height as the top of the front hoops. This is to help form a horizontal level between the front and back hoops (no dip). See the diagrams. It'll make more sense.

Now, for the third crossbar, take one of the remainder pieces of PVC Conduit (the ones with the bell ends). Take one of the remainder 1/2" white PVC pieces and stick it into the bell end of the Conduit piece. Then just cut the Conduit so that the total length of the combined piece is about 4' 2" to make a crossbar. You could cut a new piece from a fresh pipe if you want, but this makes use of the scraps you already have.

You'll eventually duct this to the top/back of the back hoops -- but don't do that just yet. Wait until after you've made the skin and put it on. There's always a little variance with how far the skin will reach in the back.

Step 8: SKIN

Time to make a hippo skin suit. Insert bad Silence of the Lambs reference here.

If you know how to sew, this will come easy to you. If not, just follow along. The general idea is that you'll have three pieces to the skin. One panel for the left side, one for the right, and one on top. You'll "sew" them all together, then flip the whole thing inside out to hide the seams. Just like sewing a pillow.

Take one of the plastic tablecloths and hold it up to the side of your hippo skeleton. That friend of yours will come in handy again here. Using a marker, trace the outside outline of the hippo with an additional 2 inches offset. Then stack another tablecloth under this one and carefully cut out both of the side panels at the same time, cutting with an additional 2 inches outside the marker line.

Now take the 3rd tablecloth and drape it over the top of the hippo, starting at the floor at the nose-end and going toward the back. It won't cover all the way to the bottom of the back -- this is intentional. You'll be left with an open doorway in the back of the hippo head. Trace the outline of the edges with a marker just like you did with the side. No cutting on this one. The 54" wide tablecloth should be exactly the right side for this design.

Take clear plastic packing tape and place it all along the marker lines (just estimate for the panel that doesn't have marker). This tape will act like reinforcement (like a grommet or like those little adhesive rings you used to stick on three-hole-punched paper for your high school binder which never quite worked well but made you feel better anyway. But in this case, the packing tape WILL work.

Time to "sew." I used a Euro-Sealer bag sealer to do the sewing. It's essentially a heating element that fuses plastic together. I've seen similar toys-- I mean, tools, in Japanese dollar stores (Daiso). If you can't find one, you can use a stapler and just staple all along.

Starting with a side panel and the top panel, line up the very front (nose end) so that the marker lines are on top of each other, and the packing tape is facing outwards on each piece. Run the Euro-Sealer along the path of the tape, just slightly inside of the marker line so that when you flip it inside out, the marker line will be hidden with the inside seam. Go slow, and make sure it's fused. If using a stapler, staple every inch or so.

Repeat with the other side panel, making sure the packing tape is facing outwards again. When you're done, flip the whole thing inside out, and make sure the seams are clean.

And now you have a hippo suit.

Place the skin over the hippo skeleton, and use clear packing tape to secure it to the bottom frame. Now you can duct-tape on the rear cross-bar where the top back of the skin ends.

If the top of the head sags, you can run a few lines of packing tape between the two hoops at the very top to form support for the skin above.

You're almost done.


For the ears, take the scrap piece of tablecloth and make a mini-pillow. You can just tape it together, no need for the Euro-Sealer here. Fill it with scrap paper, bubble wrap, packing peanuts, Chee-tos, or whatever you got. Tape them to the hippo.

For the nose, use scrap pieces of tablecloth again, and roll them up and connect the ends to make two donuts. Tape those into place as well.

Finally, the eyes. Files attached. Download, print, cut, tape.

And now your hippo should be looking pretty darned fine. If not downright hungry.

Step 10: GAME

Here's the Hungry Hungy Hippo game, if you're interested. As you can see from the photos, the field is a square area with lines that extend from the corners outward to form 4 quadrants. Four teams, four hippos. Each team has a "Feeder" in the center square who wears a corresponding color vest that incapacitates their arms. Beach balls are thrown in the middle by the game operators, and the Feeders have to kick or use their heads to send the balls toward their respective quadrants. The hippos are operated by two people who pick them up and "eat" the beach ball by pulling back on it. A fourth player then collects each eaten ball into a trash bag. Other items can be thrown into the mix, like plush baby hippos -- accidentally eating one of these leads to negative points.


And when you're done, you can hold Hippo Jousting events. Big disclaimer here. DO NOT DO THIS. Serious injury possible. Proceed at your own risk. No seriously, don't do this.

Having said that, have fun.

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    3 Discussions


    2 years ago

    Did not know that the grey pvc was more flexible than white. I thought they were the same material and the only difference was the wall thickness, or schedule, schedule 80 being thinner and more flexible than 40. You're saying it also makes a difference plumbing vs electrical?

    I made a greenhouse one with 1/2 inch white. It worked good. I used staples. I do not recommend the staples. The eurosealer looks cool. I know staples would work but im thinking clear tape would be better. Especially if kids are using them. You know how parents freak out about scrtatches, tetanus, etc. Will also be impossible to take the staples out without destroying the material, but with heat or tape it could be made take apartable. very nice detailed instructable and cool design!


    Reply 2 years ago

    Thanks, avocadostains! There's definitely something different about the gray vs. the white, at least at Home Depot. They're both Schedule 40, so same thickness, but the gray is more flexible. Anyone else know the particulars?

    I love my Eurosealer. I've seen similar sealers at Daiso (Japanese dollar-type store). You're right, a stapler is far inferior at doing the job, but OK in a pinch.


    Reply 2 years ago

    Wow, the instructables notification system could use some tweaking. I did not even know you replied to my comment. I cam back to say that I think I got it backwards, schedule 80 is typically thicker. I never even considered the conduit stuff for projects and it has the slip fitting built right in, no need to buy couplings. Pretty cool. Yea, I need a euro sealer. Never heard of Daiso. I live in Ohio.