Catnip is their feel-good plant of choice. I planted some once and the local cats went wild for it. Killed it dead and then rolled around on the corpse.
It's one of those ridiculous concepts but I didn't stop laughing. They do go into other animals but the focus is alien antics while investigating cat peak perfection in the universe.
10/10 if you a cat person and like over the top anime comedy. No romance, no action, just crippling cuteness.