Innate Spellcasting. The couatl's spellcasting ability is Charisma (spell save DC 14). It can innately cast the following spells, requiring only verbal components:

At will: detect evil and good, detect magic, detect thoughts

3/day each: bless, create food and water, shield

Magic Weapons. The young couatl's weapon attacks are magical.

Shielded Mind. The young couatl is immune to scrying and to any effect that would sense its emotions, read its thoughts, or detect its location.

Bite. Melee Weapon Attack: +2 to hit, reach 5 ft., one creature. Hit:  4 (1d4 + 2) piercing damage.

Change Shape. The young couatl magically polymorphs into a humanoid or beast that has a challenge rating equal to or less than its own, or back into its true form. It reverts to its true form if it dies. Any equipment it is wearing or carrying is absorbed or borne by the new form (the young couatl's choice).

In a new form, the young couatl retains its game statistics and ability to speak, but its AC, movement modes, Strength, Dexterity, and other actions are replaced by those of the new form, and it gains any statistics and capabilities (except class features, legendary actions, and lair actions) that the new form has but that it lacks. If the new form has a bite attack, the couatl can use its bite in that form.