Wikipedia
The Tymbrimi are a fictional extraterrestrial species in David Brin's Uplift Universe. One of the few races to ally with the humans, the Tymbrimi are considered by many of the galactic races to be tricksters. Tymbrimi have one client species, called the Tytlal, which were previously thought to be un upliftable. The Caltmour, the species which uplifted the Tymbrimi, were exterminated in a galactic war.
Physically, they resemble anthropomorphic foxes, with fur that terminates in a widows peak above the bridge of their nose. They have a multitude of tendrils that radiate out from their temples that serve as sense organs for some type of telepathy described in the books as 'empathy glyphs', in addition to radiating excess body heat.
It would seem that the Empathy Glyph is a "psychic/emotional" energy field/transmission that has an emotional content/message. Those who are capable of reading/receiving the field/transmission (Who are empathic) receive the emotion as intended by the sender. Hence should two individuals be trying to communicate, and failing to do so, one might craft an empathy glyph "The Futility of Communication" and the other would receive it, and hence realise that their failure to establish successful communication was not deliberate, but due to differing world-views.
The Tymbrimi have glands that can release enzymes for making physical changes to their appearance and organs. This is called a "gheer reaction" in the books.
Culturally, they share many of the same reservations that humans have about the effects of the Galactic Library on developing cultures.
The Tymbrimi were the first species discovered by humans, on the slow ship Vesarius.