Shark tattoos are good on a foot or ankle. Great whites, hammerheads are popular. A shark bite or shark teeth are alternative designs.

Here is a pic of a shark tattoo I did for West Side Story that the Lady Sharks wore.This is a picture of the actual tattoo that the girls wore, I printed it on temporary tattoo paper (it's the mirror image).

I tried adding some shading and got this version. It's okay, but I'll work on it some more.

I've seen various versions of this shark, usually with a lot more detail, kinda tribal in nature. So, here's a simpler design.