My partner makes one! Go grab a copy if you're in Australia, the wonderful POP local -- started as POP Canberra -- sells them.
https://www.poplocal.com.au/product/bum-man-colouring-book/
He's 'Bum Man'. A man (actually it's asexual) who is a bum. I mean c'mon.
Looks cool, but they should show more of the pages online. All I see is the (already coloured) front cover.