headcannons for genitals
I think it might be tentacle-ish if its needed for females it would hide inside of an opening not dissimilar to a vagina, in the male the tentacles are more pronounced and do not hide but there is a small flap in the taint area for other males. and the breasts on female are just enlarged glands hiding extra fat from grubhood so the more a grub ate the bigger their size some how that process only happens for females no matter what. so once they become trolls they are all skinny. wbut the men are a bit more meaty all around.
Height Cannons - all pretty similar in size though except Tavros and Nepeta
Tavros-pre leg amputations / robot legs
Eridan and Kanaya
Aradia and Sollux