Displacer Kitten and Throne of Eldraine on the battlefield.
({2} magic symbol) ({G} magic symbol) ({G} magic symbol) if Throne of Eldraine's chosen color is not "Green" available.
Steps
If able, activate Throne of Eldraine's first ability by tapping it, adding ({G} magic symbol) ({G} magic symbol) ({G} magic symbol) ({G} magic symbol) that can only be spent to cast green monocolored spells.
Cast Wurmcalling with buyback by paying ({2} magic symbol) ({G} magic symbol) ({G} magic symbol) .
Displacer Kitten triggers, blinking Throne of Eldraine. Choose "Green" as it enters the battlefield.
Resolve Wurmcalling, creating a 0/0 Wurm creature token and returning Wurmcalling to your hand.
The Wurm enters the battlefield and dies as a state-based action due to having 0 toughness.