My only objection to "hominid" is that it has a very specific meaning which most (all?) of the animal people don't meet - namely, being an ape, which requires being a primate, which requires being a mammal, which requires being a vertebrate, etc. Calling a gorilla person a hominid would be fine, but calling a slug person a hominid would make my science hurt.
"An upright, slug-like person" perhaps? Could also go with something more like the vanilla description of demons with furry bodies, e.g. "A slug twisted into humanoid form."
I'm still a bit concerned about "diminutive," as it makes me think, like, gnome-sized. "Half the size of a human" might work, except that it might imply half the
height of a human, which is almost certainly incorrect. I don't have a good answer without, like, a fantasy humanoid volume-to-height-ratio calculator.
...oh hey I can model that very roughly with a cylinder.
This textbook I found on google uses a h/r ratio of 12 for a cylinder modeling a human, so sure let's go with that.
This would mean that to calculate the height of a humanoid of volume V Urists^3 the formula is
h = (144V/pi)^(1/3)
Since a human is 70,000 U^3 in volume, we can model that a human is 147.49 U tall. Since an ideal human figure is about 8 heads tall, we can model roughly how far up on a human a given humanoid would be by comparing its U height against the height of a human head, 18.437 U.
Results:
35,000 U^3 humanoids (e.g. mosquito men) are roughly 117.06 U tall, or 6.3496 human heads. They'd come up to above a human's nipples.
45,000 U^3 humanoids (e.g. dingo men) are roughly 127.29 U tall, or 6.9044 human heads. They'd come up to a human's chin.
Obviously this assumes an identical volume distribution between humans and each given humanoid, which will need to be compensated for in the case of particularly non-human-like animal people - e.g. legless animal people are going to be significantly shorter than calculated, as they maintain their thickness throughout their bodies, instead of having relatively low-volume legs to increase their height.