Green’s Dictionary of Slang

(US) one who makes wounding, cruel remarks.

1974		R. Blount About Three Bricks Shy of a Load 110: I’m a cheap shotter in a way.
1984		Chicago Sun-Times 27 Jan. 106: It was the same Doug Plank who forged a reputation [...] around the NFL as a head-hunter, late-hitter, cheap-shotter and loudmouth [HDAS].
2002		Simulation Hockey League 1 July 🌐 The Kings will try to shake things up next game but ‘yours truly’ thinks he’s gonna be wrong again in his prediction... Indeed the Stars will win but in 6 rather than in 7 ! Nice job Wilks... You cheap shotter you!