WTF too short!

Nice for a begginer, you should try easing. You need to improve at drawing, there are a lot of tutorials to check out.

Good worm motion, but try to put the worm on the ground and maybe a slight pause when it moves. so the head moves the tail catches up and the head moves again.

Well, first of all; Was it a worm or a snake?
Work more with the background and with shades, that's what gives animations "more life"!
Good first attempt, but remember! The more work behind it, better it get!

Keep on! :)