Activate Genku by paying ({3} magic symbol) ({W} magic symbol) ({U} magic symbol) , putting two +1/+1 counters on each creature you control due to Lae'zel, Vlaakith's Champion.
Activate Cryptic Trilobite's first ability twice by removing two +1/+1 counters from it, adding ({C} magic symbol) ({C} magic symbol) ({C} magic symbol) ({C} magic symbol) that can only be spent to activate abilities.
Activate Crystalline Crawler's first ability twice by removing two +1/+1 counters from it, adding ({W} magic symbol) ({U} magic symbol) .
Repeat.
Once you have infinite ({C} magic symbol) , you may forego removing counters from Cryptic Trilobite.
Results
Infinite +1/+1 counters on all creatures you control except Crystalline Crawler.
Infinite colorless mana that can only be spent to activate abilities.