TV Monster: Sweetums

Sometimes I wonder about Sweetums’ back story before he joined the Muppet Show. Was he a mean monster turned softy after a particularly traumatic experience? Had he always been a sweet monster; was that part of how he was as a species? Or, was he an outcast from his aggressive family? I usually think of him as an outcast because, for the majority, all of the Muppets are outcasts, and he finds his family among them. Oh, Sweetums!