Lion

A lion as ally is most often a druid's wild shape, a ranger beast companion, or a sacred animal bonded to a temple of a sun or hunt deity. Mechanically it contributes mobility and intimidation. A lion pacing into a frontier town parts the militia without a word. A lion at 50 ft. of speed outpaces the party's mounted scout. In combat, use two Rend attacks at +5 doing 1d8+3, and Pack Tactics trigger when another PC is within 5 ft. of the target.

Running Leap is the signature move. The lion bounds 25 ft. to reach a creature that seemed safe, Rends twice, then leaps back out before retaliation matters. This is how the lion generates action without managing complicated mechanics.

Out of combat, build the bond in specifics. The druid sleeps with one hand on the lion's flank. The temple's lion does not cross the inner sanctum threshold because that is the rule. The ranger's lion refuses to fight summoned enemies from other planes. Concrete details turn a stat-line companion into a campaign character.

Name the lion in session one. A nameless lion is a prop. A named lion is a death the table will mourn.

A lion is a CR 1 ambush predator. 22 HP, AC 12, walk speed 50 ft., Stealth +4. It has Pack Tactics for advantage on attacks when allies are nearby and Running Leap for 25 ft. jumps off a 10 ft. sprint. Multiattack is two Rend attacks at +5 doing 1d8+3 slashing each, or replace one Rend with Roar, a Wisdom save DC 11 that leaves a target Frightened until its next turn.

The encounter is the charge, not the trade. If the party sees the lion first, they win. If the lion sees them first, somebody is on the floor before initiative matters. Set up the surprise with tall grass on a savannah trail, a rocky overlook above a dry riverbed, or a ruin reclaimed by the wild. Roll Stealth at +4 against passive Perceptions; if the lion wins, the first character within 50 ft. is grappled and prone before they get a turn.

Run them in pairs or prides. One lion is a quick kill for any party past level 2. Two lions splitting the party's attention, with one charging the cleric and one pinning the fighter, is a real fight at levels 1 to 3. Pride hierarchy gives a free retreat trigger: drop the alpha and the rest scatter at 50 ft. of speed, and the party will not catch them. Use Roar to panic anyone trying to flank; a Frightened PC loses advantage on attacks and can't willingly move closer.

A wounded lion breaks off and runs. If the campaign returns to that region later, the same scarred lion can be back, stalking the party instead of charging.

Describe the sound before the sight. A cough in the grass, a low rumble from the rocks, then nothing. The drama is in the pause.