The Claykken (or just Claykken) is a Boss from Kirby and the Rainbow Curse, appearing at the end of Indigo Ocean and Red Volcano. His name is a clay-spin on 'The Kraken', and as such, resembles a giant squid.
On top of his base design as a squid, The Claykken's head resembles a pirate captain's hat, and he has a small mouth near the base of the tentacles with a smoking pipe inset. The Claykken also has a number of scars on his body, presumably from previous battles.
When The Claykken appears again, he has a different color scheme and a more elaborate hat. He is also sporting an eye patch and more scars.
The Claykken spends most of his time in the background, first trying to attack by sending his arms in through a hole to reach Kirby and try to swipe at him. The tips of the arms are covered in spikes, but the rest of the arm is vulnerable, and can be dashed into.
Once the Claykken has taken enough damage to his arms, he will opt to charge in full-body. He spins about like a missile, and will attempt to crash into Kirby. His head is impervious, but his rear is vulnerable, so Kirby has a chance to hit him after the Claykken has jammed his head into the wall.
The Claykken is fought twice - with the second fight taking place outside of the water, and over a crumbling bridge with lava beneath. The environmental change alone is enough to change the dynamic of the fight without The Claykken needing any new attacks.