a teaching/research 'fellow' [=a graduate student who gets money in exchange for teaching/research]
He attended the concert with a 'fellow' student. [=someone who is a student, as he is]
He has always tried to be of service to 'his fellow man'. [=to other people]
(..) just us toys. I'd better take a look anyway. Why is that soldier strapped to an explosive device? That's why, Sid. Sure is a hairy fellow. No, no, that's Scud, you idiot. That is Sid. -You mean that happy child? -That ain't no happy child. He tortures toys, just for fun! (..)1995 Toy Story