The Grim Adventures of Billy and Mandy (2001)

Season 6: Episode 9

When Billy gets his kite stuck in a tree, he starts throwing objects at it to knock it down, including Mandy and a group of three boy scouts, but all objects get stuck too. Frustrated, Billy and Grim call a druid for help, who in turn trains them to become druids, so the three of them can perform a ritual. Meanwhile, inside the tree, Mandy battles a group of squirrels, and leads the scouts back to the ground. Since the druidic chants did not work against the tree, the druid goes ahead and uses a chainsaw to bring the tree down, but this gets him arrested.