You have at least one +1/+1 counter on a creature you control.
Mana Needed
({1} magic symbol) ({G} magic symbol) available.
Steps
Activate
Ooze Flux by paying ({1} magic symbol) ({G} magic symbol) and removing a +1/+1 counter from a creature you control, creating two 1/1 Ooze creature tokens, which will enter the battlefield with two +1/+1 counters each due to
Doubling Season and
Master Chef.
Rosie Cotton of South Lane triggers twice, putting two +1/+1 counters on
Crystalline Crawler and any creature you control due to
Doubling Season.
Activate
Crystalline Crawler's first ability twice by removing two +1/+1 counters from it, adding ({1} magic symbol) ({G} magic symbol) .