Elephant

An elephant as an ally serves best as a mount or a laborer, not a primary combatant. Its 40 ft. speed and 76 HP make it a capable steed for a knight or a noble, but in a fight the creature is herd-social and easily distracted. A lone elephant in pitched battle will try to rejoin its group if one exists nearby, even if ridden.

If the party's elephant is mounted and combat starts, it can move and act normally. An elephant ridden by a character with strong bond (a ranger's companion, a paladin's mount) will trust its rider's cues. But most elephants were trained to haul and carry, not to kill. Gore and Trample are available if cornered, but don't count on them being used aggressively without specialized training.

The useful play is the elephant as a wall or a mover. It occupies a Huge amount of space, can shove creatures out of the way with Strength plus 2, and clears terrain the party cannot. Its Gore attack works if the elephant charges something, and Trample works if an enemy lands Prone, but these are defensive options. Let the party use the elephant for what it is: transport, a body big enough to block a doorway, and muscle for hauling.

Once the fight ends, assume the elephant is tired. A ridden elephant cannot be pushed into a second combat without at least an hour of grazing and water. When the elephant dies, the rider takes a check to dismount safely or takes falling damage from a Huge body collapsing beneath them.

An elephant runs combat through charging and following up with Trample. It moves 40 ft. a turn on flat ground, enough to close from a distance and trigger its Gore knockdown. Gore requires the elephant to move at least 20 ft. straight toward the target, lands at plus 8, deals 2d8+6 piercing on a hit, and if the target is Huge or smaller it falls Prone. Once something is on its back, Trample finishes the job on your bonus action: a DC 16 Dexterity save against 2d10+6 bludgeoning, half on success.

The combo is the entire fight. Open by charging the closest target and rolling Gore. If it lands and the creature fails Prone, use Trample as your bonus action. You've now done 15 average piercing plus another 17 average bludgeoning on the same creature, and they cannot stand without burning their full turn. If the first Gore lands but they resist Prone, use Multiattack for a second Gore against the same target or a different one.

The elephant's only real weakness is spacing. It cannot charge if it cannot move 20 ft. first, so a party that corners it in tight ground or locks it in melee with backline fighters drops its damage output to a single Gore per turn. AC 12 is vulnerable to any ranged pressure. If the terrain is open and the party spreads, the elephant gets its full 40 ft. and charges cycle every round.

Run elephants in pairs or small groups if the encounter can support it. A lone elephant burns through targets quickly but can be starved for movement if the party spreads tight. Two elephants in an open field each charging different directions creates real coordination pressure.