Master Eagle is a character briefly mentioned by Po in Secrets of the Masters, and by Shifu in Kung Fu Panda 3. He/she is a credited master of kung fu.
Master Eagle was briefly mentioned in Secrets of the Masters. According to Po, Master Eagle once owned the Blade of Bao Ding, which he/she had used to defeat the Hyenas of Handan.
In Kung Fu Panda 3, Master Eagle was again mentioned, being one of the masters who sent word to Shifu at the Jade Palace after presumably falling prey to Kai and his jombies.