Since the Name Rater is full, and I have some good, and unoriginal, names, I will not use the Name Rater, because it's full, and basically blah blah blah. So, my nicknames for a Chimchar are:
Flare, Pyro, Burner, Heater, Scorcher, Inferno.
These six are all the ones I can think of for now. There's no credit needed, so you can use them freely.
I also have some names for a chimchar like rafiki, fire monkey based on the Zodiac the fire monkey, Flamer and Chimpy.