Uncle Victor and Aunt Lucy are from Nat’s side of the family, and Bea, despite her kind and caring nature, has never been too fond of them, especially after they started blatantly playing favorites in regards to her sons. Hearing them sing Donny’s praises while not bothering to even try to hide their dislike of Beetlejuice makes her want to break their frames in half.
Uncle Sid is Bea’s younger brother, and he and his wife Irma are the Neitherworld equivalent of BJ’s godparents. And while they love both of their nephews equally, they see BJ as the son they never had, much to his embarrassment.
Auntie Em married into the family.
Donny does have magic like his brother, but rather than being based on what he says, his powers are based on how he feels. And the more negative his emotions, the harder it is for him to control his powers. It’s part of the reason why he’s so positive and cheerful all the time. He doesn’t wanna risk getting angry. It could seriously get someone hurt.
Donny is altruistic to the point that it’s almost unhealthy. He’s always putting others first but hardly ever makes time for himself (when we first meet him, he tells Lydia that he gave up his own lunch to “feed the hungry multitudes”).