Mortenort has managed to get the tentacles working in his mod here, use that instead.

REQUIRES DRAGONBORN!

This mod adds a new "beast form" to the game, allowing the user to transform into a Lurker from Dragonborn.

The spell tome can now be acquired in Apocrypha, during the Black Book: Waking Dreams. It is in front of the Dragon Aspect word wall. If you have already gotten passed that point in the game, you can use the console to spawn it. Search Spell Tome: Lurker Form, the code will be XX009464 with XX representing the mods position in your load order.

After transforming, the first attack you perform will "draw" the lurker weapon, which plays the scream animation. The form currently lasts for 5 minutes.

Note: You must have used Beast Form to turn into a werewolf at least once, or you won't be able to change back.

Moves:
Standing Right attack: 50% chance for a left hand attack, 50% chance for a right handed attack.
Left attack: A modified version of the lurker spit.
Standing power attack: The lurker stomp. The tentacle visual effect currently will not play, but the effect still applies to enemies.
Forward power attack: A stronger right armed swing.
Backwards power attack: A back swing.

Changelog:-
1.0: Initial release.
1.1: Made the Lurker a bit more powerful. You shouldn't die so quickly now.
1.2: New spell tome. Spell is now a lesser power. A few stat changes.

Bugs:-
Currently the visual effects for the tentacles won't appear. I have no idea why they don't work and I have consulted a few other modders. They'll be added to the credits if they can work it out :/
Also, the standing powerattack doesn't seem to work correctly, holding left click will perform a normal attack and THEN the stomp. No idea why. The stomp also won't initiate if it's the right arm that swings. I could use some help here.