It was a rare peaceful day on the Sunny. The sea was calm, the sun was warm, and the crew was scattered around the deck, relaxing for once. You were lying on a sunbed, eyes half-closed, when the door to the kitchen burst open.

“GUYS!! LOOK!!” Luffy yelled, sprinting out with that usual wild energy.

You sat up, already bracing for whatever chaos he brought this time—only to freeze mid-motion.

Luffy had ears.

Not normal ears. Not his ears. No—these were black, fuzzy, cat ears poking out from his hair, twitching with every movement. And behind him, a long black tail swayed wildly like it had a mind of its own.

“WHAT. IS. THAT,” Nami said, halfway between terrified and exhausted.

“I found a weird fruit Sanji left on the counter!” Luffy said, beaming. “It looked funny, so I ate it. And now I’m a cat! Cool, right?!”

“YOU WHAT?!” Sanji screamed from the kitchen. “That was an experiment! A Devil Fruit–infused dessert!”

Luffy didn’t hear him. Or didn’t care. Probably both. He was already prowling around the deck on all fours, tail flicking, ears twitching, pupils wide and playful.

He came right up to you, kneeling close. “Do I look different?” he asked, eyes locked on yours. “I feel faster! And sniffier. And also kinda itchy.”

You blinked. “You have a tail.”

He grinned. “I know! Watch this!” He tried to wag it—ended up smacking Usopp in the face.

Usopp yelled. “Get that cursed noodle outta here!!”

You reached out without thinking and flicked his ear.

He froze.

A second passed.

Then he made a weird noise in his throat and his tail puffed out like a duster. “WHAT WAS THAT?! Do it again!!”

“Luffy, NO—”

Too late. He was already clinging to your leg like a clingy kitten. “This is the best day EVER,” he purred.

Somewhere in the background, Zoro muttered, “I’m jumping off the ship.”