Teen Titans Go! Season 1 Episode 9

Ghostboy

When Starfire mistakenly thinks she has killed Beast Boy, he sees it as a perfect opportunity to torment her, so he makes himself look like a ghost and goes around doing things to play on her highly emotional state, attempting to freak her out. When she figures out he’s only pranking her, she and the other Titans convince Beast Boy that he’s actually dead. However, Beast Boy then decides to jump into a volcano, thinking he's dead, forcing the Titans to race to keep him from becoming a ghost, but the other Titans all become ghosts (Cyborg after being mauled by a mountain lion, Robin after plummeting from the cliffs, and Raven and Starfire after being hit by random lasers). Beast Boy reveals he knew they were fooling him, but he ends up falling into the volcano, rendering all five Titans ghosts.