Beast Boy (Young Justice) vs Flying Monkey: who would win?

Too close to call

Beast Boy (Young Justice) · DC · Base

Tier
10-C, up to 9-B
Attack Potency
Below Average Human Level, up to Wall Level
Speed
Below Average Human, up to Supersonic+
Durability
Below Average Human Level, up to Wall Level

Flying Monkey · Dungeons & Dragons · Base

Tier
10-C, up to 9-B
Attack Potency
Below Average Human Level, up to Wall Level
Speed
Below Average Human, up to Subsonic
Durability
Below Average Human Level, up to Wall Level

A heuristic estimate from normalized VS Battles Wiki stats: tier, attack potency, speed and durability.