Temurzoa, the Progenitor

Other Jellyfish creatures you control get
+1/+1.
Whenever you cast a spell, put a +1/+1 counter on Temurzoa. If there are four or
more +1/+1 counters on Temurzoa, remove
all +1/+1 counters from it and create four
0/1 blue Jellyfish creature tokens.