Trostani, the Ascended Druid

Convoke
Whenever Trostani enters the battlefield or attacks, populate three times.
Lifelink
Whenever Trostani deals combat damage to a player or planeswalker, create a 1/1 Human Soldier creature token with lifelink, a 2/2 Elf with vigilance, and a 3/3 Centaur with trample.