Manticore tail toxin, matango spores, the city mage asking you to take questionable substances to test her alchemy skills, venefica's entire schtick, the alraunes, Feng, and the succ ninjas. Drugs are actually significantly more common than tf. I'd even argue that the transformation content is non-existent, since at least 2(?) of the enemies are just wearing a disguise and Perpetua going through her villain arc. Slimes are amorphous by nature, so saying she "transforms" is like saying you transform by growing 6 inches.