Raven

A raven on the party's side is almost always somebody's familiar, somebody's omen, or somebody's mail courier. 2 HP, AC 12, fly 50 feet, Perception +3, passive 13. Beak at +4 does 1 piercing. Mimicry lets it imitate simple sounds like a whisper or chitter, with a DC 10 Wisdom check to discern the imitation. It cannot fight. The reason it earns a tab is that ravens carry more session-time than their CR 0 deserves.

Use the raven for vision and delivery. Fly 50 feet with its single Beak attack means it is purely a tool: scout the next room, drop a note on a windowsill, watch a meeting from a beam. Find Familiar lets a wizard see through its eyes as an action, which turns a 2-HP bird into a free reconnaissance loop. Don't roll initiative with the raven on the field. The moment a hostile spell goes up, it flies for the rafters.

Lean on lore. A raven that has spent time with a wizard tends to mimic words. That is roleplay, not a stat ability. Players love a familiar that says "key, key, key" at the locked door, and they remember it for years.

Give the raven one specific behavior the player invented: it lands only on the left shoulder, it steals shiny coins, it clicks at every cat.

A hostile raven is almost never a single bird. It is a witch's pet sent to scout, a corpse-eater on a battlefield the party is searching before nightfall, or the warning that a flock is coming. 2 HP and a Beak for 1 piercing means a thrown rock kills it.

Run the raven as a problem the party cannot solve cleanly. It watches from a tree just inside 50-foot fly range and reports back to whoever sent it. The witch knows exactly which way the party turned. The hag knows which PC is wearing the locket. Players will want to shoot the bird and should be allowed to, but every dead raven means a new one arrives within the hour. The pressure is surveillance, not combat.

If the party kills the bird and tries to read the corpse for clues, give them an omen. A raven sent by something Fey or Fiendish leaves a marker: a black feather that won't burn, a smear of ink-like blood, a single human tooth in its crop.

Have the same raven appear three sessions in a row before anyone shoots it.