Red Dragon Wyrmling

A red dragon wyrmling on the party's side is a stretch but a fun one. The framing: the party rescued the wyrmling's egg from poachers, killed the older wyrm that was bullying it for its share of a cave, or caught it stealing from a market and bargained for its life. Chaotic Evil is still the alignment. The wyrmling is loyal in the moment because the party is currently the most useful thing in its life, and loyalty will end the second a more useful thing arrives.

In combat, the wyrmling is a glass cannon that loves the spotlight. Open with Fire Breath for the dramatic clear if your party isn't standing in the cone, which is your job to manage as DM. 15-foot cone, DC 13 Dex, 7d6 fire on a fail. Set it up so the wyrmling can fly 30 ft. up, breathe down a corridor, and clear the orcs without melting a PC. If the party isn't sure where the wyrmling is going to point, that's the joke: the wyrmling is also not sure. Multiattack is two Rend attacks at +6 for 13 damage each plus the 1d6 fire rider, and the wyrmling will land for melee against anything wearing armor it considers shiny.

The wyrmling will demand a share of every hoard. Treasure is the entire reason it tolerates the party. Refuse it, and it sulks; cheat it, and it stops showing up; murder its share, and it ambushes the party in their sleep three sessions later. Run the loot conversations explicitly. The dragon gets first pick of the gold and one magic item.

Give the wyrmling a name it picked itself, in Draconic, that it insists everyone use in full. The bit lands every time.

A red dragon wyrmling is the first real boss most parties will face, and it should hit like one. CR 4, 75 HP, AC 17, fly speed 60, immune to fire, and a 7d6 cone breath weapon that averages 24 damage on a fail. A level 3 party of four can win this fight, but somebody is going down.

Open with Fire Breath if it's available, which it always is round one. DC 13 Dex save, 15-foot cone, 24 fire on a fail and 12 on a success. Position the wyrmling so the cone catches at least two PCs, ideally including a wizard or rogue who fails the save and eats most of their HP pool. Fire immunity means you can stand on burning oil, scorched timber, or a hot brazier with no penalty, so set the encounter in a forge, a kobold-tended bonfire chamber, or its own nest of charred bones. The terrain is your second damage type.

After the breath, use Multiattack for two Rend attacks at +6, 1d10+4 slashing plus 1d6 fire each, averaging 13 per hit. The wyrmling is intelligent enough (Int 12) to pick targets: hit the cleric, then the cleric again, then break off if a paladin closes. Fly 60 ft. lets it pop up to 30 feet of altitude after a melee turn so the party's frontliner has to either ranged-attack, climb, or wait. The Climb 30 means it can also wall-crawl in a low-ceilinged cave, which is a great way to make a tight fight feel claustrophobic. Recharge 5-6 on Fire Breath means it will fire again, often round two or three. Don't forget to roll.

Wyrmlings flee. They are children with a hoard of stolen silverware and an inflated sense of self, and they are not ready to die for a pile of coins. Once Bloodied, fly straight up and out, taking the silver bowl in its claws. It will be back at adolescent CR 10 in five years of game time, and it will remember.

Write the wyrmling's hoard down in detail. The players should remember stealing the music box, because the dragon does.