Khinto, Master of Poison

Wither (This deals damage to creatures in the form of -1/-1 counters.)
Whenever a creature an opponent control dies, if that creature had a -1/-1 counter on it, create a token that is a copy of it except it's a 1/1 Illusion Scarecrow with infect.
Whenever one or more poison counters are put on a player, create a 1/1 green Snake creature token with