Elk

An elk ally is a druid's mount, a wild shape, a ranger's animal companion in a homebrew setting, or the gift of a forest spirit who told the party "follow this stag and you will find the river." The framing that works best is the gift, because elk are not pets. They tolerate riders briefly, they bolt at sudden noise, and they will leave the party the moment the road feels wrong.

Mechanically there is almost nothing in the stat block. No actions. The elk is a 50 ft. mount that carries a Medium rider through forest at speeds the party's regular horses cannot match. Use it for one specific journey, not as a permanent acquisition. In combat, dismount the rider. The elk has 11 HP and AC 10 and dies to a single hit from anything that's a real threat. Have it run when the violence starts, then return at the end of the scene if the party calls for it.

Out of combat, the elk is a Perception asset (passive 12, Darkvision 60 ft.) for night watches and a navigation aid in dense terrain. A druid PC can communicate with it via Speak with Animals to get one-line answers about what's downwind.

When the journey ends, the elk leaves at the treeline. If a player tries to keep it as a permanent companion, let the elk wander off on the third night when no one is watching. The point of the elk was the trip, not the pet.

An elk is wilderness texture, not a fight. CR 1/4, AC 10, 11 HP, no listed actions, just a Walk speed of 50 ft. It hits things by Shoving with Strength 16, and a single ruling-on-the-fly hoof or antler attack lands maybe 1d6+3. The right way to use an elk as adversary is to never put it in initiative, or to put a herd in initiative for one round and then let them run.

Use an elk in three scenarios. First, the random encounter that isn't a fight: a bull elk on the trail in rut, antlers down, blocking the only path. Animal Handling DC 12, Intimidation DC 14, or detour. Second, the herd stampede: the party flushed twenty elk by being noisy, and now the druid's bear and the rogue both need to make Dex saves not to get trampled while the elk run past at 50 ft. Treat the stampede as terrain, not enemies. Third, the wounded animal that injures someone careless: a hunter PC tries to finish a downed elk and the GM rules a desperate kick. Make it cost 1d6 and a small lesson.

Elk rout instantly. WIS 10, no traits, no immunities. A loud spell, a sudden fire, or a single drawn blade sends them running, and they run faster than the party. Don't make the players grind one. If you've put an elk in front of them, the answer should be either roleplay or a single skill check.

Have the bull elk lock antlers with the party's strongest fighter for one Athletics contest, then let it disengage with whichever side won the roll. Either outcome is a story.