Board Thread:Questions and Answers/@comment-202.150.1.24-20130417103156/@comment-94.59.232.84-20131111053939

In BTD Battles, 1/2 sniper monkey.

In BTD5, Monkey apprentice, Dartling gun, Signal flares upgrade mortar tower or bomb tower with a monkey village with radar scanner upgrade.

Note that the ones i said worked in BTD5 work in BTD battles too, but they can appear earlier in BT5 battles and it's hard to get those ones by then.

And you don't have to unlock sniper monkey, it's there from the start.