People who start fires intentionally are called pyromaniac or pyromania. These people are then most likely to start a fire by arson, in which they would then be considered arsonists.
you call them bitefull
a traveller...
belligerent
Pyromaniac.
a geologist
geek
sharp
a traveller...
There is no special name for a person who likes squirrels.
a troublemaker?
How about a "gun enthusiast"?
blademaniac