I'll start out by saying that all the tabs on diff sites are wrong 
in most ways for Tommy the Cat, if you listen to the song there 
is only one that I've tried playing that comes close, I'm just 
going to leave the main riff because the rest of the tabs have 
the rest of the stuff right (or I can't see how they can be improved)

The Key:
D= Downward Strumm
U= Upward strumm
S=Slap
(3)=Muted Slap (on 3rd fret, if two musted slap twice)
P=Pop


And here is the riff:
G—————2——4————————————————————————————————————————————|
D—————4——4————————————3h5——————5———————5—————5——————0—|
A—————————————————————————————————————————————————————|
E———————————0h3——(3)———————(3)————(33)———(33)———(33)——|

that's pretty much it, it took me a while to get it, and it takes 
a while to get used to the speed that claypool plays