Dire Wolf

A dire wolf companion is a ranger's bond, a druid's wild shape, or a goblin chieftain's mount the party negotiated for. The animal is not a pet. It tolerates the handler and respects the food source. If the handler dies, the wolf does not stay loyal to the party out of grief, it leaves, and the players should know that going in.

In a fight, the wolf is a flanker. Walk speed 50 ft. lets it get behind anything, and a pack tactic in the fiction (you only have one wolf, but you can play it as if it's hunting) means the smart play is to attack a target the rogue or barbarian is already engaged with. The wolf bites, the rogue gets advantage from the flank, the barbarian gets a clean shot at the back. AC 14 and 22 HP means it can take one or two hits before the handler needs to call it back, so don't park it in front of an ogre.

Out of combat, the wolf is the party's scout and tracker. Perception +5 and Stealth +4 are real numbers at low levels, and Darkvision 60 ft. means it can range ahead at night without a torch. Have it return to the camp every few hours rather than tail the party every step. The image of the wolf melting back into the trees and reappearing at dawn with mud on its muzzle does more for the bond than any combat round.

Have the handler name the wolf at the table the first time it shows up. Players remember named animals.

A dire wolf is a pack predator with the stat line of a low-level martial. Run one alone and it's a forgettable speed bump. Run three or four together and the party is suddenly being out-positioned by something that should not be out-positioning them. The dire wolf has Stealth +4, Perception +5, Passive Perception 15, and Darkvision 60 ft., which means at night in the woods the pack sees the party long before the party sees the pack.

Open with an ambush. The wolves close at 50 ft. of walk speed from two directions and try to isolate the rear of the party, which is usually the wizard or the herbalist with the lantern. Whoever they hit first gets the worst of it. AC 14 and 22 HP per wolf is enough that a level 2 PC won't drop one in a single turn, so the math says you keep the pressure on the same target across two rounds. Drag the body out of the firelight if you can. A pack that fights for meals doesn't waste them.

Wolves break when the pack alpha falls. Designate the largest one as the leader, and once it's bloodied or dropped, have the rest disengage and run. This is true to wolf behavior, it gives the players a satisfying inflection point in the fight, and it gets the encounter off the table before the party slogs through 22 HP each on the last two animals. A retreating dire wolf is a dire wolf that comes back tomorrow night with friends.

If you want a memorable fight, give one wolf a scar from a previous fight with a hunter, and let the players notice it after the kill. Wolves with stories register as more than HP bags.