This tab is from a pretty good recording of Nature Boy taken from primussucks.com from what is I believe the Woodstock show.

Um, I don't know how the whole song goes as recorded on Pork Soda, but I saw that this song wasn't tabbed already so I did my best to contribute seeing as I come here often.

Sometimes when the intro riff is repeated during the chorus, he uses a wah, like in the intro, duh.

Intro Riff
e--------------------------------------------------
b--------------------------------------------------
g--------------------------------------------------
d--------------------------------------------------
a---7-6------------------------------------7-6-----
E---------6-6-9-7-6---4-4-4-7-6----6-6-9-----------

Chorus
e---------------
b---------------
g---------------
d--9-8-8//4-4---
a--7-6-6//2-2---
E---------------

The first B power chord (the 2, 4 one) may be palm muted. I find it sounds better that way. When I pick up Pork Soda I'll take a stab at the whole song solo and all.