Professor Anna Nekaris, of Oxford Brookes University, led the team of international researchers who made the discovery in Borneo and the Philippines.
She said: "The slow loris might look like a harmless, big-eyed Ewok from a scene in Star Wars, but the animal is actually one of the only poisonous mammals in the world.
"Its toxin can cause death in humans through anaphylactic shock.
"Unknowing humans should stay clear of the toxin, which is released from near its elbows. When threatened, the loris takes the toxin into its mouth and mixes it with saliva."