Bawb'rah (w/ Whistle + Feats)

Keen Hearing and Smell. The dog has advantage on Wisdom (Perception) checks that rely on hearing or smell.

The Goodest Boy. The beast obeys you commands as best as it can. It takes its turn on your initiative. On your turn, you can verbally command the beast where to move (no action required by you). You can use your action or bonus action to verbally command it to take the Attack, Dash, Disengage, or Help action. Once you have the Extra Attack feature, you can make one weapon attack yourself when you command the beast to take the Attack action. If you don't issue a command, the beast takes the Dodge action.
If you are incapacitated or absent, the beast acts on its own, focusing on protecting you and itself. The beast never requires your command to use its reaction, such as when making an opportunity attack.

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 8 (1d6 + 5) piercing damage.

Claw. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 (2d4 + 5) piercing damage.

Teleport (Recharge 4–6). The dog magically teleports, along with any equipment it is wearing or carrying, up to 40 feet to an unoccupied space it can see. Before or after teleporting, the dog can make one bite attack.
This trained blink dog specializes in rescue from the Blink Dog Training Fife: it can choose to take a friendly creature within 5 feet of it when it teleports in place of making a bite attack.

Displace (Recharge 4–6). Bite attack; no damage, but teleports target 15 ft (Beast Trainer Feat)

Charge: Bonus action dash (Beast Trainer Feat)