The Hellhounds.

They're Crowleys' absolute favorite beings, even above himself. But being the King of Hell, he can't always be home to take care of them. He knows they're not exactly of the mortal realm so they don't really need to be cared for like normal dogs, but he likes to spoil them.

Anyway, he'd entrusted you, his most loyal, (and most tolerable,) to take care of the hounds when he's away, and he's never ever had a complaint. One day, he's looking for you so he can ask a question, and he finds you cuddled up with the hounds.

Not only that, but there's also new pups. A lot of them.