Tentacle Morph

Upon casting this spell, you touch a creature and transform its arms into long, writhing tentacles. For the duration of the spell, the target’s reach increases by 5 feet. The target gains advantage on Strength (Athletics) checks made to grapple creatures, and it can use its tentacles to make unarmed strikes. If it hits with them, it deals bludgeoning damage equal to 1d4 + its Strength modifier, instead of the bludgeoning damage normal for an unarmed strike.

At Higher Levels:
When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d4 for each slot level above 2nd.