The Bat

Can only be equipped by, Scout, Force of
Nature.
Equipped creature gets +0/+4 and has Evolve (Whenever a creature enters the battlefield under your control, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.).
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)