Agent Venom

Haste, Vigilance, Symbiote (When this creature enters the battlefield, it deals 2 damage
to other creatures you control. They gain +3/+1
and symbiote, unless they already have it, until
this creature is destroyed. If you control no other creatures, at the end of your turn destroy this creature and put a 3/1 Symbiote creature token
in its place.)