Well, thanks a lot, Madawc, now I have to spend the rest of the weekend painting Michaela’s bedroom in lavender plaid.
Stupid gambling addiction. . .
No, I think you are thinking of when Plankton accidentally fell into the machine he was going to use for finding out what a Krabby Patty was made out of. He fell in, got zapped, and the computer said-
Plankton:
2% Evil
98% Hot Gas
It was this same machine that showed us that Seaweed is in fact 50% sea, and 50% weed! So all you cynics can just suck it! 
I’m pretty sure the episode was this one
http://www.tvtome.com/tvtome/servlet/GuidePageServlet/showid-3428/epid-164607/
but there isn’t much to make my statement fact. The synopsis is a one-liner. And reading the viewer comments, shrimp seems to be mentioned here and there. I’m quite sure the patty is of plankton.
In this episode, Plankton gathers a whole army of plankton (his family, a large one) to take over Krusty Krab. I think they get slaughtered by Mr.Krabs and used as patty mix, with all this to the horror of Plankton himself. I think that’s what happened, not 100%sure now. Since I live in Canada, we get to see some of the episodes not aired already in the States. I only saw this plankton patty episode once and now I’m not sure if I even saw it at all hehe.
Incubus I remember that show, but I’m pretty sure it’s not the one I’m recalling. TV tome seems to be weak on the Spongebob episode guides… I’ll try and find that episode you mentioned in TV tome but again, it’ll be tough since the synopses are so weak.