Mugwump
From Archon Arcana
Mugwump • Brobnar • Creature • Rare • After an enemy creature is destroyed fighting Mugwump, fully heal Mugwump and give it a +1 power counter. • Artist: Nicholas Gregory • Card Number: CotA (042), AoA (044), WC (043)
Commentary
Regardless if Mugwump was the attacker in a fight, if Mugwump survives a fight, its ability will resolve.
Source: Timing Chart•Fight