The first thing I made when I got my 3Doodler (after a cube and some scribbles) was a spider. I thought it came out fairly good so I decided to post it on instructables. To make the spider you need some skills with a 3D printing pen but you needn't be an expert. How well the spider comes out depends on how steady our hand is and how good your art skills are.
Step 1: Materials
The main thing you will need to make the spider is a 3Doodler (or other kind of 3D printing pen). A 3Doodler is a kind of pen that extrudes 3D printer filament. You will need about three strands of filament. Four if you plan to make the spider web. Of course, you may need more or less depending on how large your spider is. Three pieces is enough for a two inch spider. Two strands of one color and one of another color seems to look good but that's just my opinion.
Step 2: Doodle the Spider
Start by forming two ovals, one about three times the size of the other. Start building up layers until the ovals are domed. Repeat for the other side. To make the legs start extruding filament into the space between the two ovals and then pull upwards. Repeat until you have the desired number of legs. Normal spiders have eight legs but mine only has six due to the fact that I.couldn't fit anymore than that. After you have the first segments of legs done make the bottom segment by first pressing the tip of the pen to the end of the first segment. Just like before, extrude a small amount of filament then slowly pull downwards. If some legs are longer than others, the problem can be easily corrected by trimming them with scissors. To add eyes simply make small dots with the pen. Mandibles are made the same way as the legs but with more layers added to make them thicker.
(The seemingly different colored spiders are a result of my pathetic camera combined with my poor photography skills.)
Step 3: Make the Web (optional)
Making a web isn't really necessary but I recommend it since the spider's legs can't really hold its body. Start by doodling a small blob then draw something like eight spokes coming out. Arch a line between each spoke until it goes all the way around. Repeat this until the web is mostly filled in. Make a tower in the middle about the height you want your spider to be. Finally, extrude some plastic between the spider and the tower to attach them.