Keen Senses. The pseudodragon has advantage on Wisdom (Perception) checks that rely on sight, hearing, or smell.

Magic Resistance. The pseudodragon has advantage on saving throws against spells and other magical effects.

Shadow Health. The pseudodragon transforms with a number of temporary hit points equal to half the sorcerer level of the person who transformed it.

Shadow Stride.  The pseudodragon can move through other creatures and objects as if they were difficult terrain. The hound takes 5 force damage if it ends its turn inside an object.

Relentless Pursuit. At the start of its turn, the pseudodragon automatically knows its target’s location. If the target was hidden, it is no longer hidden from the pseudodragon.

Shadow Frenzy. On its turn, the pseudodragon can move only toward its target by the most direct route, and it can use its action only to attack its target. The pseudodragon can make opportunity attacks, but only against its target. Additionally, while the pseudodragon is within 5 feet of the target, the target has disadvantage on saving throws against any spell you cast. The pseudodragon reverts to normal it is reduced to 0 hit points, if its target is reduced to 0 hit points, or after 5 minutes and instantly returns to its master.

Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 4 (1d4 + 2) piercing damage.

Sting. Melee Weapon Attack: +4 to hit, reach 5 ft., one creature. Hit: 4 (1d4 + 2) piercing damage, and the target must succeed on a DC 11 Constitution saving throw or become poisoned for 1 hour. If the saving throw fails by 5 or more, the target falls unconscious for the same duration, or until it takes damage or another creature uses an action to shake it awake.