Crystalline Crawler has at least four +1/+1 counters on it.
Mana Needed
({G} magic symbol) ({U} magic symbol) available.
Steps
Activate
Vorel by paying ({G} magic symbol) ({U} magic symbol) and tapping it, doubling the counters on
Crystalline Crawler.
Activate
Crystalline Crawler's first ability three times by removing three +1/+1 counters from it, adding ({G} magic symbol) ({U} magic symbol) ({U} magic symbol) .
Activate
Pemmin's Aura's first ability by paying ({U} magic symbol) , untapping