I'm not sure I really need to elaborate on this question much, masters Tigress, Viper, Crane, Mantis, and Monkey are all named after the animal that they are when almost no-one else in the fictionalised setting seems to be (indeed actually no-one in the first movie) , not even Po, the only known giant panda at the time.
Even (most of) the other kung-fu masters aren't named like this (e.g. Oogway rather than Turtle, Shifu not Red Panda, Tai-lung rather than Leopard.)
There are a few other kung-fu masters named after their animal most notably Chicken, Porcupine, Boars in Kung-Fu Panda 3 and a few other assorted masters in the Legends of Awesomeness TV show. There are also masters "Flying Rhino" and "Thundering Rhino" though I'm discounting these as flying and thundering seem like the sort of things that would distinguish someone sufficiently rather than referring to their entire species.