Mullins is a human man living in Neverland.
Behind the scenes
Loosely based on the character of Robert Mullins from J. M. Barrie's original Peter Pan novel and play, Mullins debuted in 1953 in Peter Pan. Robert Mullins is killed by Captain Hook in the novel, whereas Mullins presumably survives in the film.
For unknown reason, several Tortooga Pirates, including Gentleman Starkey and Moody, are lookalikes of Mullins.