I present to you a character from a series of humane monster underwater.
The character has animations and excellent textures.
For full functioning of the tentacles to Unity, you will need a Dinamyc Bone
https://assetstore.unity.com/packages/tools/animation/dynamic-bone-16743
ANIMLIST https://drive.google.com/open?id=1u1UI-7DQigmCLlmlCv-lBzPTJPD9QEfY
Monster underwater 01
PBR textures.
-Albedo
-AO
-Metallic
-Normal
(all 4096-4096 size)
Polys:21,103
Tris:41,064
Verts:20,733
Original_Link: https://assetstore.unity.com/packages/3d/characters/creatures/monster-underwater-01-192029