Baro Astacar

{g}: Baro Astacar becomes a 1/1 rat creature with unblocable until end of turn.
{g}{g}: Baro Astacar becomes a 2/2 wolf creature with vigilance until end of turn.
{g}{g}{g}: Baro Astacar becomes a 3/3 tiger creature with first strike until end of turn.
{g}{g}{g}{g}: Baro Astacar becomes a 4/4 bear creature with trample until end of turn.