Vadrik and Crystalline Crawler on the battlefield.
Vadrik has a power of three or greater.
Crystalline Crawler has at least one +1/+1 counter on it.
({U} magic symbol) available.
Steps
Cast Clockspinning with buyback by paying ({U} magic symbol) , putting a +1/+1 counter on Crystalline Crawler and returning Clockspinning to your hand.
Activate Crystalline Crawler's first ability by removing a +1/+1 counter from it, adding ({U} magic symbol) .