Might of the Froghemoth

You have developed traits similar to those of a froghemoth, granting you the following benefits:

Ability Score Improvement. Increase your Strength or Constitution by 1, to a maximum of 20.

Froghemoth's Expertise. You gain proficiency in Perception or Stealth, alternatively you can gain darkvision out to a range of 60 feet. If you choose Perception, but you already had proficiency in Perception you gain expertise in it instead.

Amphibious. You can breathe air and water. In addition, you gain a swimming speed equal to your walking speed.

Resilience of a Froghemoth. When you finish a long rest, you can choose to gain resistance to fire and lightning damage for 24 hours. However, while you have these resistances and you take lightning damage, your speed is halved, you take a −2 penalty to AC and Dexterity saving throws; you can't use reactions; you can't cast spells of 1st level or higher; you can take either an action or a bonus action on your turn, not both; and regardless of your abilities or magic items, you can't make more than one attack on your turn.

Froghemoth Form. As a bonus action, you can transform, growing larger and sprouting a pair of tentacles from your shoulders, which lasts for 1 minute. While transformed, you gain the following benefits:

• If you are smaller than Large, you become Large, along with anything you are wearing. If you lack the room to become Large, your size doesn’t change.
• You have advantage on Strength checks and Strength saving throws.
• You gain a tentacle attack, which has a reach of 15 feet and uses your Strength modifier for attack and damage rolls made with it. On a hit, it deals 2d8 bludgeoning damage, and the target is grappled (escape DC 8 + your proficiency bonus + your Strength modifier) if it Large or smaller. You can't make an attack with a tentacle that is grappling a creature.

You can use this feature a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.