Vekra, The Scavenged Hope

Hexproof, Trample, Vigilance, Infect, Riot
When a creature dies, create a 2/2 Zombie token,
when a Zombie dies, create a 1/1 Saproling toke with "{t} sacrifice this for one colorless mana"
All creatures you control have vigilance, a +1/+1 counter, and all creatures that enter the battlefield has riot