slang A highway patrol officer who has only recently started in that line of work. Possibly a reference to Smokey the Bear, a cartoon character who wears a hat similar to those sometimes worn by the highway patrol. I can't believe you let that baby bear give you a ticket—what a rube.
baby bear
n. a beginning highway patrol officer; a rookie cop. (see also Smokey (the Bear).) Some baby bear tried to arrest me for speeding, but I conned him out of it.