Ruby Gloom Season 2 Episode 15

Skull Boy's Persona: Misery's Cousin Murky

Misery's relatives - Names and descriptions:

Mayhem - Cavewoman; previously seen in the episode, Time Flies.
Mildew - Geisha
Migraine - Snobbish lady who lives on a cruise ship; previously seen in the episode Time Flies.
Morose - Goth/Emo archetype
Myopic, Malice & Misbegotten - Tiny, cheerful triplets.
Mopey - The optimistic one. Looks like Misery with a wig resembling Ruby's hair (as seen in the episode Ruby Cubed). She only appears in one scene.
Malady - Disease prone; previously seen in the episode, Misery Loves Company.
Malaise - Narcoleptic; previously seen in the episode, Misery Loves Company.
Murky - Skull Boy pretending to be Misery's cousin, probably because he misses having a family of his own.

Since this eventually turns out to be a dream sequence, there's a possibility that some of these relatives may be long dead, or existing only in Misery's imagination.

This episode revolves around Misery.