Cockroach

Telepathic Bond. While the cockroach is on the same plane of existence as its master, it can magically convey what it senses to its master, and the two can communicate telepathically.

Spider Climb. The cockroach can climb difficult surfaces, including upside down on ceilings, without making an ability check.

Cockroach Fortitude. If damage reduces the cockroach to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is fire or from a critical hit. On a success, the creature drops to 1 hit point instead. 

Rejuvenation. If it dies, the cockroach returns to life in 1d4 days and regains all its hit points. Only a wish spell can prevent this trait from functioning.

Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 3 (1d4 + 1) piercing damage.

Intimating Presence. You can use your action to frighten someone with your menacing presence. When you do so, choose one creature that you can see within 30 feet of you. If the creature can see or hear you, it must succeed on a Wisdom saving throw (DC equal to 8 + proficiency bonus + your charisma modifier)  or be frightened of you until the end of your next turn. On subsequent turns, you can use your action to extend the duration of this effect on the frightened creature until the end of your next turn. This effect ends if the creature ends its turn out of the line of sight or more than 60 feet away from you.

Dash. Gain extra movement for the current turn. The increase is equal to your speed.

Hide. Make a Dexterity (Stealth) check in attempt to hide, following the rules for hiding.