Create a mesh (e.g., a cone-shaped cube with many loop cuts) and apply a Curve Modifier . This allows the tentacle to slide and deform along a path, which is often smoother than using an armature.
To achieve a professional "anime" look, apply these stylistic principles: How I Animate a Scene from Beginning to End
Use the Puppet Position Tool to place pins along a straight tentacle illustration.
The movement of tentacles is typically achieved through specialized rigging rather than standard limb armatures. 3D Workflow (Blender)
Use an Array Modifier with an "object offset" (using an empty) to create a tapering effect where the tail gets thinner toward the end.