Panther

A panther as ally is the classic Find Familiar (alternate companion) for warlocks of the right pact, a ranger beast companion, or a druid's wild shape choice in jungle and forest campaigns. With Stealth +7 and a 50 ft. walk plus 40 ft. climb, the panther is a perfect scout and shadow, and the player who picked it almost certainly did so because they want to be the kind of character who walks beside a big cat.

Out of combat, give the panther work that uses the stat block. She climbs the wall to scout the temple roof. She pads ahead through the jungle and signals back when there is movement. She holds Stealth in a copse while the rest of the party makes noise on the road, and the panther's player gets a free flank if the bandits commit. Rule that her tracking gives Advantage on Survival checks to follow a scent in wet terrain.

In combat she is fragile. AC 13 and 13 HP means a single goblin crit can drop her. Use her for one assist, not for a full combat shift. The classic move is the pre-fight pounce: the panther sneaks ahead, drops on the lookout, and silences the alarm before the rest of the party rounds the corner. After that, she should disengage and stay out of melee while the bigger PCs trade.

If she dies, take a beat at the table. The player picked a panther for a reason, and the loss should be a scene, not a line in the recap.

A panther is a CR 1/4 stalker with 13 HP and the highest Stealth on this section of the bestiary, +7. The stat block lists no actions, so the encounter is the ambush. Treat the panther's bite as a Medium beast unarmed strike at the GM's discretion, and design the scene around the part the stat block actually supports: getting close without being seen, then dropping on someone.

Use the geography. Walk 50 ft. and climb 40 ft. mean the panther starts on a tree branch or a rafter, watching the party walk underneath. Roll Stealth at +7 against passive Perceptions; if the panther wins, the first PC within 50 ft. of its drop point is on the ground with a cat on top of them before they get to act. At low levels that single round can end someone.

Run the panther as the executioner of a larger jungle scene, not as the whole encounter. A scout cult uses one as their tracker. A drow patrol has trained one to climb walls in the Underdark and pounce on the party's torchbearer. The panther costs 50 XP and is a CR 1/4 line item, but it changes the texture of the bigger encounter completely.

The panther flees as soon as it is hurt. With 13 HP it cannot trade and it knows it. Once a PC connects, the cat breaks off at 50 ft. of speed, climbs the nearest vertical surface at 40 ft., and is gone before the party rolls initiative for round two. The party will not catch it. That escape is the encounter, because the same panther can come back the next night.

Describe the smell of cat before you describe the cat. Damp fur, blood, wet leaves. Players who think to look up have a chance. Players who don't, don't.