I'm trying to identify a picture book I remember reading around 1999, which included a set of cartoonish creatures (diseases?) invading a body.
Each page included a different area (starting with the scalp and ending with the brain, I think), with some of the creatures either adapting to the new environment or being eliminated.
The back of the book included a graph showing where each creature evolved and where it was eliminated.
I can only remember two of the creatures: one was a smiling (orange coloured?) head with arms that swung on the hair in the scalp page, but quickly died off thereafter. The other was a brownish head with limbs and a helmet (which I believe covered its eyes) that made it through until the brain before having to evolve, at which point it randomly became a robot that blended in to the other robots (IIRC the brain was some sort of computing facility staffed by robots with a different number of red 'eye' lights than the helmeted disease one).
If it helps, I read the book in Australia. I think the book was also A4 sized, each page being all artwork.
It's been a long time since I saw it, so those are all the details I can remember. Hopefully they're enough for someone with a better memory or who owns the book to recognise it.