yeap, when I earned it, I got the 0 $ CCU from Cat to Pirate Cat, expecting never to own a Cat. I was wrong, so my Cat became a pirate CatUnless CIG has changed their mind.. the Pirate skin Cat is non-giftable (as @marcsand2 ) shows, and while I am often wrong don't think there has ever been a CCU.. you gotz to EARN the right to spend your money on this one.
Having said that, Pirate Swarm in a reasonably co-operative group is not difficult; it is likely to be harder when the new Master Modes come into the game as the Hammerhead should be harder to survive.
Edit: No way I can think of to get LTI on it, so I've not 'collected' one.