Keen Smell.  The kitten has advantage on Wisdom (Perception) checks that rely on smell.

Darkvision.  The kitten has Darkvision to a range of 30 feet.

Ball of Wool.  The kitten can be completely distracted from any task if it encounters a ball of wool, which it will play with.  If this happens, the kitten must be physically removed from the ball of wool to stop it playing.  If it is left to play with the ball of wool for more than 30 minutes, it will fall asleep and will be unable to be awakened for 4 hours.

Telepathic.  You can communicate with the kitten telepathically.  You and it can understand each other perfectly when using this method of communication.

You Always Have Me.  If the kitten dies for any reason, a new kitten will appear at your side the next dawn.

The kitten has no attack capability at all.

I iz only a Kitten.  As a reaction, the kitten has the ability to appear perfectly harmless.  If this ability is used, no creature will attack it or, if an attack has already begun, the creature will stop the attack before damage is done.  The creature will ignore the kitten from then on.
The kitten can still be damaged by effects or spells that do not target it, such as Area of Effect damage.