Jr. Troopa, the Unstoppable

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.)
Whenever Jr. Troopa, the Unstoppable evolves,
choose either flying, deathtouch, vigilance, or
lifelink. Put one of those counters onto Jr. Troopa.
"I'm your worst nightmare! Here comes the pain!"