Paleosuchus

They live in swamps, but most of them are neutral mobs that are often in the water.
Of course, it is hostile when attacked by the player.
Also, because the body is very stiff, it is very difficult to defeat, and even if you defeat it, you will lose only a small amount of experience points.
You can swim quickly and walk slowly on land, but you can run faster if you get angry.
Of course, as long as the player doesn't attack this mob, it's okay, so you can pass it.
By giving this mob rotten meat, you will gain trust and temporarily help the player.
If you have any other good ideas, please let us know in the comments.
Thank you for looking at my idea