Homebrew Cephilid Species Details

Ability Score Increase: Your Intelligence score increases by 2, and your Dexterity score increases by 1.
Size: Small
Speed: 20 feet, Swim 35 feet, Climb 15 feet
Amphibious: You can breathe both air and water, but you will dry off if you are out of water for too long.
Wet Skin: You need to be watered every 6 hours (in game) or you will start to dry. When you are dry, you take double physical damages, and loose 1 hp every turn or minute (in game).
Tentacle Dexterity: You have a set of flexible tentacles that provide you advantage on Dexterity (Sleight of Hand) checks.
Ink Cloud: Once per short rest, you can release a cloud of ink as a reaction when you are attacked. This cloud grants you partial cover until the start of your next turn.
Water Camouflage: You have advantage on Dexterity (Stealth) checks made while underwater.
Aquatic Affinity: You have advantage on saving throws against being grappled or restrained while underwater.
Jet Propulsion: Once per short rest, you can use your tentacles to propel yourself forward, gaining a swimming speed of 60 feet for one round. Additionally, you can use this ability on land, allowing you to dash as a bonus action.
Languages: You can speak, read, and write Aquan, you understand, read and write Druidic but cannot speak it, you understand Common but can't speak it 

Cephilid Traits

Octopus Traits

Ability Score Increase

Your Intelligence score increases by 2, and your Dexterity score increases by 1.

Size

Small

Amphibious

You can breath both air and water.

Wet Skin

You need to be watered every 6 hours (in game) or you will start to dry. When you are dry, you take double physical damages, and loose 1 hp every turn or minute (in game).

Tentacle Dexterity

You have a set of flexible tentacles that provide you advantage on Dexterity (Sleight of Hand) checks.

Ink Cloud

Once per short rest, you can release a cloud of ink as a reaction when you are attacked. This cloud grants you partial cover until the start of your next turn.

Water Camouflage

You have advantage on Dexterity (Stealth) checks made while underwater.

Aquatic Affinity

You have advantage on saving throws against being grappled or restrained while underwater.

Jet Propulsion

Once per short rest, you can use your tentacles to propel yourself forward, gaining a swimming speed of 60 feet for one round. Additionally, you can use this ability on land, allowing you to dash as a bonus action.

Languages

You can speak, read, and write Aquan, you understand, read and write Druidic but cannot speak it, you understand Common but can't speak it