Which verb should I use and why?

Question

Either the wild dogs or the baboon makes or make that howling sound.

I think since dogs is plural it should be make?

Answer 1

There's a tricky rule when the conjunction in a compound subject is "or" --

The verb needs to match the subject that is closer to it in the sentence; in this case, "baboon" is closer to the verb, so you use the singular verb form.

Answer 2

See #5 here:
http://grammar.ccc.commnet.edu/grammar/sv_agr.htm