Zyra, Thorn’s Embrace

At the beginning of your upkeep and whenever a
creature an opponent controls dies, create a
"Thorn spitter seed" token or a "Vine seed"
token.
Whenever you cast a sorcery spell, you may
transform all "Vine seed" tokens you control.
Whenever you cast an instant spell, you may
transform all "Thorn spitter" tokens you control.