Tentacle Lash

4th-level biomancy*

Casting Time: 1 action
Range: Self
Components: V, S, M (a miniature plunger)
Duration: Concentration, up to 1 minute
Class: Druid, Ranger, Warlock, Wizard

One of your arms elongates into a long, wet, suckered tentacle. When you cast this spell, and as an action on each of your turns, you can make a melee spell attack against a creature within 30 feet of you. On a hit, the target takes 5d8 bludgeoning damage and it must make a Strength saving throw if it is Huge or smaller. On a failure, you can choose one of the following effects:

• The target is knocked prone.
  
• The target is shoved 5 feet in a direction of your choice.
  
• You disarm the target; you take one item the target is holding and return it to your person.
  

The tentacle also serves as an appendage that can be used like a grappling hook or rope (GM’s discretion).

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the damage increases by 1d8 for each slot level above 4th.

*can be replaced with transmutation
Source: Heliana's Guide to Monster Hunting