Kakuzu
There were many reasons why he didn't like his partner Hidan. Really. And one of them had to do with squids.
Hidan had just become his partner at that time and they had been at the sea. They had been peacefully walking over the ocean, when his partner suddenly started talking. That wouldn't have been that bad, if he had shut up after some time. But, unfortunately, he hadn't.
Kakuzu, who had grown more and more irritated by the blabbering, tried to threaten the Jashinist with the threads which held Kakuzu's body together. The Akatsuki member just laughed at him, and that was the moment when he had said it. It.
"You know what, Kakuzu? Your threads look like tentacles."
Poor Kakuzu had been so surprised that he forgot to pump chakra into his feet and fell right into the water.
The problem: Kakuzu could not swim.
After lots of snickering from Hidan, lots of swearing from Kakuzu and a lot of trashing around, they managed to continue their journey.
As an 'apology', Hidan had treated him with sea food as they reached the coast. He didn't tell the older male that he was paying with his money, not even to this very day.
A very grumpy Kakuzu had waited an eternity for his meal, in which he tried to get at least a little bit more comfortable in his cloths that were soaking wet.
So when the food was served, the money-(and at the moment food-) hungry criminal immediately started eating.
But then he halted for a moment and looked more closely at WHAT he was eating.
It looked...slippery...
It was. A squid. And squids have tentacles.
Kakuzu at that moment couldn't help but think of the comment his partner had made. With a slightly disgusted look in his eyes, he had glanced at his arm, then back at the squid on his plate. At his arm. Back at the squid.
All of a sudden, his appetite was gone.
(He could never look at his threads the same way ever again.)