The Thunder Tree is a tree that only appeared in the Season 7 episode "A Long Tale For Grandpa". It lives on Thunder Island far away from the Smurf Village, that stamps with a root on the Earth and is guarded by two yellow Octopians, who served their king, Lord Squird. With the magic balloon, Grandpa Smurf and a few Smurfs travel to the island to find the tree and take its sap, which is needed to defeat a swarm of hungry insects called aphids that attack the Smurf Village.