OH! i actually only think void-based creatures are null (entirely due to the circumstances of their birth... in a way the concept reminds me more of how minerals form than any living being!) as for everyone else... for most that i don't assume to have either cloaca or some strange alternate mating system (pedipalps...) i opt for just a kind of long, smooth, needledick with no permanent external features and a very simple like... pink line pussy. they are simple creatures, a simple dick is fitting... most people opt for stubby conedicks but i feel for most of the characters with their squat little bodies that would be kind of awkward to get in... thusly i tend to make them a lot longer and thinner than most (but not like... enough to look crazy i don't think?)
as for favorite characters... largely it follows that rule although funnily like. 2 of the characters where i think it's quite different are ones i pair together LOL... i want taranza to have cute little pedipalps, and i just think uh. i've drawn it before but essentially susie's body is shapes such a way that. she has kind of. female dolphin genital slit situation. but that's entirely because of the strange conclusions i've come to about what she's even actually SHAPED like. shes kinda like a tsuchinoko even. i don't know.... i know most of these are very much based in me going like "well this is what makes sense so-" sorry if that is not as interesting as you had hoped LOL