Welcome to “Firefly Fun House,” where Rambling Rabbit is alive somehow, Mercy the Buzzard is impatient, Abby the Witch is grumpy and Bray Wyatt has a secret. The former WWE Champion opened the latest installment of his eerie children’s show by promising to play “Secret Time,” where he offered to show what he’d really been working on during his time away — learning how to harness and control the darkness rattling around in his noggin. And with the apparent blessing of his fireflies, he let his new self in, transforming from a genial fellow in a sweater into a ghoulish figure in striped pants, a leather duster and a fanged mask. Yowie wowie, indeed.