Be Cool, Scooby-Doo! - Season 2

Shaggy's friend Amelia invites Shaggy and the gang to a party. But Shaggy discovers that Amelia has become a goth. After realizing he has feelings for her Shaggy starts to feel bad that he hasn't changed at all so he decides he too will become a goth. But a mystery appears when an evil plant monster attacks the gang.