Renaming the Cat

Snippet of an actual conversation chez moi:

As Starman walks in the room holding the cat . . .

Me: You know that residential facility where my client's son is? Bridgeview? Well, the staff aren't much older than the residents, so they have to be called Mr. or Ms. and then their first names. You'd be Mr. [Starman] and he'd {indicating the cat} be Mr. Linus.

Starman: But Linus is his surname.

Me: No it's not. {Thinks to self, I was there when he was named, but says instead . . .} If Linus is his surname, what's his first name?

{pause}

Starman: Lionel

{longer pause, while I laugh, hard}

Starman: And he's the Earl of Barfalot.