Bagman

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

Grappler. The Bagman has advantage on attack rolls against any creature grappled by it.

Amorphous. The Bagman can move through a space as narrow as 1 inch wide without squeezing.

Regeneration. The Bagman regains 10 hit points at the start of its turn. If the troll takes acid or fire damage, this trait doesn't function at the start of the troll's next turn. The troll dies only if it starts its turn with 0 hit points and doesn't regenerate.

Alien Mind. If a creature tries to read the Bagman's thoughts, that creature must succeed on a Intelligence saving throw DC 17 or be stunned for 1 minute. The stunned creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Extradimensional Horror. Anytime The Bagman grapples a creature while still in its bag, that creature must pass a DC 18 Strength check. On a failed check, The Bagman pulls that creature inside its bag. A creature inside a bag can use its action to try to escape with a successful DC 20 Strength check. Another creature can use its action to reach into the bag to pull a creature out, doing so with a successful DC 22 Strength check. Any breathing creatures that have spent more than a number of minutes equal to 10 divided by the number of creatures (minimum 1 minute), begin to suffocate. 

Multiattack. The Bagman makes three attacks: one with its bite and two with its claws.

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 7 (1d6 + 4) piercing damage.

Claw. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) slashing damage, and the target is grappled (escape DC 18). Until this grapple ends, the target is restrained, and the Bagman can’t attack with its claw.