Tank transporter Puns

So a guy decides he wants to buy the world's most unique pet. He goes to the pet store.

He looks at a cat and a dog. Not unique enough.

He looks at a hamster and a guinea pig. Please.

The pet store guy shows him a porpoise in a tank. He says "what's unique about that" and the pet store guy says "this one will live forever".

So he buys two.

He takes them home and puts them in his bathtub.

He feeds them. He tries feeding them fish, shrimp, waffles, everything. They won't eat anything.

So he goes back to the pet store, and says "they won't eat anything I give them" and the pet store guy says "Oh yeah, I forgot to tell you, the only thing they will eat is mynah birds."

He says "mynah birds. Really?" and the pet store guy says "yep".

So he buys a couple mynah birds and takes them home.

When he gets home, there's a lion sleeping on his front step. Yes, a lion.

He thinks, that's a little strange, but I've got these mynahs and I've got to feed my pets. So he steps over the sleeping lion and takes the mynahs inside.

Just then, a cop jumps out of the bushes and arrests him.

He says "come on! What's the charge"

And the cop says

"transporting mynahs across a sedate lion for immortal porpoises"