Or is it a gear? Either way these are fun little shapes to make with your 1x2 Lego bricks.

Step 1:

To make a lovely Lego cog of your own, you will need:
-288 1x2 bricks

Two color: 144 of each color
Three color: 96 of each color

Step 2:

Sorry folks, no easy strips to connect or stack to attach together, this shape is usually easier to just build. The upside is that it's kinda fun to build and easy to keep count of.

We'll be working from the bottom up. Start with the brick you want in the bottom row (white in the picture) and attach two bricks to it as shown.

Use 3 more white bricks and 2 more blue bricks and make em look like the third picture.

The goal here is to basically make a square zig-zag chain with 5 studs (those are the dots on top of the bricks) on each side.

Keep adding bricks until your model has a few turns in it then meet me over at the next step.

Step 3:

Now that you have the shape laid out a little you can add the top row of bricks (dark blue in the picture).

Continue the square zig-zag pattern until you only have 2 bricks left (a top row color and a bottom row color). If you're counting then you'll be aiming for 12 cog sticker-outer things (teeth?).

Note: You want the end of the square zig-zag chain to have a middle brick sticking out, as shown in the picture. This is important for the Close Er Up! Step coming up next.

Step 4: Close Er Up!

Bring the two ends around to meet each other. Use the remaining top layer brick to connect the two sides then add the last bottom row one. BAM! You're done! Have some coggin fun :)

Want more 1x2 LEGO fun? Check out these other 1x2 bendy shape Instructables:
Lego Star
L ego Saw Blade
L ego Deltoid and Astroid
L ego Pentagon
L ego Triangle
L ego Circle
L ego Starburst
L ego Medical Sign
L ego Heart