
I tested the kraken boss in the game.
You can compare the regular kraken and the boss in the video.
(This was supposed to be a GIF, but it's probably too heavy for file-sharing sites.)
https://i.imgur.com/fOsLJtF.mp4
Here's how it looks on the battle arena.

And here's a comparison of it and the "tallest" creatures in the game.

Added 2 minutes later
The other animations also don't work well with the new kraken (they get stuck in the surroundings a lot), and they will have to be redone. There will only be basic animations: walking, attacking, taking damage, and death.
It's possible that the kraken boss will have to be slightly reduced in size.