Our own Perry the Platypus from Phineas & Ferb.
He's a platypus. He doesn't do much. However, the kids LOVE him.
They love him so much, in fact, they fought over him at first. Annabelle would even call him "Annabelle's Perry." We taught her that Perry was the whole family's platypus and how we all need to share and love him.
He even makes noise.
The kids do it back.
Every night, he keeps the living room safe from any non-welcomed guests. I've actually found myself cuddling with him after the kids go to bed. Personally, I think he's the perfect pet. No clean up. That would make any Mom happy.