That is, they use the vomit as a distraction?
Humans
Humans - best defense against rape is a BM, pee or vomit. All three at once will deter any rapist.
I suspect apes do it when stressed, but I don’t have any cites.
Sure, the Fulmar (foul gull) for one. It can yak up to 5 feet at a perceived threat.
A gull is a mammal now?
Naw, whales are mammals. Gulls are fish:D
Aw heck, sorry about that, misterW. I was tryin’ to leave for the day and thinking animals in general. Thanks for the catch, HJ.
According to Medieval bestiaries, a beast called the Bonnacon used to deter its pursuers by “voiding its bowels, and covering the ground with a great fart.” Different end of the animal, but similar ploy. The beast appears to be some sort of antelope. The description goes back to Pliny:
T.H. White, in his wonderful The Bestiary: A Book of Beasts notes that “many animals defecate when fleeing”, which is probably the origin of this story. Not really as spectacular as the Bonnacon (the descriptions in the link above are more extravagant than what I quote), but plausible.
I once met a girl who did it when she panicked, Amy Segal, the girl had g… uh fortitude. 
CMC fnord!
I thought the best defense against rape was RapeX, now with extra thorns.
Llamas. They are said to spit, but its actually regurgitated stuff from the stomach.
The camel does that. It generates a huge stinky loogie and spews it in your face.
I find either analytical or absurd replies work with human animals.
Or, for humor, try “I’m not worth it!”
I’m pretty sure I have read about a mammal using long range spitting (but closer to a vomit than just a gobble) to warn off attackers (it was a non lethal but poisonous spit vomit). I think it was a Northern critter, like a wolverine, the thing is, as I remember it, it was an animal from Prehistory.
Really cant remember the name though.
It’s also a great way to get out of jury duty.
Turkey vultures. Hoopoes (does spraying shit-like goo from the back count?). Pygmy sperm whales (ditto, but could be ink-like screen). There was a recent Cracked.com article (with photos, yum!) on this topic.
In high school, a friend named Blair said to the teacher “May I be excused from class; I’m on my period.” The teacher said “No,” so Blair vomited on the teacher.
The confusing thing about it was that Blair was male.
All the camels (dromedaries, llamas, alpacas etc) will vomit on predators if they are attacked. While there is a myth that camels will spit on animals that annoy them, it isn’t saliva, it is projectile vomit.
Many of the opossum type marsupials will vomit on themselves in an attempt to make themselves less appealing to predators.
Frat boys.