You are a Monstrosity.

You are medium or small

Your walking speed is 30 feet.

Endless modifications to your very being have molded your mind and infused you with innate psychic power.

• You become resistant to Psychic damage, and increase your Wisdom, Intelligence, or Charisma score by 2. You also add +1 to any ability score of your choosing.

• You gain the ability to cast Detect Thoughts without expending any spell slots once per long rest (DC 8 + your proficiency bonus + the ability modifier of the score increased by this trait, or for spellcasters, whatever your spell save DC is). You can also telepathically communicate with any creature within 60 feet of you, provided you can see them. This does not give them the ability to respond telepathically, and they can only understand you if you speak in a language they know.

• You gain the ability to cast Mage Hand without any components, along with the hand becoming invisible if you choose. You can also expend a bonus action to try and telekinetically shove a creature within 30 feet of you. This fails if they succeed a Strength saving throw (DC 8 + your proficiency bonus + the ability modifier of the score increased by this trait, or for spellcasters, whatever your spell save DC is).

• You gain the ability to telekinetically move objects by extending your hand, and focusing on the target and how you want it to move. This can be done at will without expending anything beyond your focus.
  • As you level, you become more proficient at manipulating objects. At level 1, you can move your own body weight. At level four, you can move 100 pounds. At level 8, 200. Level 12, 400. And you peak at level 16, able to carry 1000 pounds at will, at a time.
  • In combat, this takes up a full action.
  • When attempting to move an unwilling creature, make an ability check with your spellcasting ability, or Strength if not a spellcaster, contested by the creature's Strength check. If the creature fails, they are constrained until their next turn where they can contest again. If you fail, the creature is released from your grasp and you cannot attempt to move them until your next turn.
  • I personally give your DM full permission to hit you with the exhaustion ray if you overwork your dumb psychic cat. There is no specific stats for this, I just think it'd be funny.

I am unfortunately not very good at using D&D Beyond. You can just manually add the ability modifiers in your sheet.

Because of your psychic abilities, you have a flying speed equal to your walking speed. You can’t use this flying speed if you’re wearing medium or heavy armor.

You have a second neck, attached from the nape, to the back of your head. Full of nerves, veins and arteries. If it is grabbed, roll a D20.

If you roll above a 6, your body will go limp until your neck is released. Though, with regular training, this can be increased to a 10.

Your makers cared much more about creating a superweapon than creating a sustainable being.

Your body runs at a temperature that makes equipping Heavy or Medium armor completely impractical. You gain disadvantage on all rolls with it on.

(Frankly, I suggest ignoring or replacing this trait. I just couldn't think of a way to balance out the rest of the sheet.)