they are 18

Wendy is a witch-oni hybrid, so are Bebe, Heidi, Red, and Nicole, Kyle is a vampire-medusa hybrid, having his eyes covered by bandages, Cartmen is a siren, Kenny is a zombie, Stan is a werewolf-spirt, Craig is a memitim-grim reaper hybrid, Butters and Jimmy are ghoul-vampire zombie hybrid, Tweek is a demon, Tolkien is a griffin-beast hybrid. (this isnt mine its Simpy_Topa but i made it better in my opinion)