Small to Large semiaquatic animal (your creature type doesn't change),
Armor Class: 10 + your Wisdom modifier
Hit Points: you continue to use your hit points and hit dice
Speed:
20 ft
, swim: 40 ft
Skills: DEX equals your wisdom Score
Your other scores use your scores
Proficiency bonus equals your proficiency bonus
Amphibious. You can breathe air and water
Senses: Darkvision 90ft.
Languages: the languages you know
Actions
Multiattack. You can make two Bestial Strike attacks
Bestial Strike. Melee Attack: your Spell Attack Modifier to hit, reach 5ft., one target. Hit: 1d6 + your Wisdom modifier Bludgeoning, Piercing, or Slashing damage.