Mezlan

Polyglot — A mezlan can speak and understand any language they hear spoken after listening to the language for 1 minute. These languages fade from their mind after 24 hours.

+1 Status to All Saves vs. Magic —

Regeneration 15 (Deactivated by Acid) — This monster regains the listed number of Hit Points each round at the beginning of its turn. Its Dying condition never increases beyond Dying 3 as long as its regeneration is active. However, if it takes damage of a type listed in the regeneration entry, its regeneration deactivates until the end of its next turn. Deactivate the regeneration before applying any damage of a listed type, since that damage might kill the monster by bringing it to Dying 4.

Absorb Spell — A willing caster can allow the mezlan to Absorb a Spell without requiring a save.

Discorporate — When the mezlan is reduced to 0 Hit Points, their body dissolves into colorless slime and begins seeping into nearby cracks or porous surfaces.

If this material is not immediately contained or destroyed, the mezlan will eventually re-form, though they may lie dormant for years or even decades before doing so.

Change Shape (concentrate, polymorph) — The mezlan assumes the form of any Medium or Small creature, excluding those with the elemental, incorporeal, or swarm traits but including specific individuals whose appearance they've seen. This doesn't change the mezlan's Speed or their attack and damage bonus with their Strikes, but the damage type dealt by their Strikes might change based on their new form.

The monster changes its shape indefinitely. It can use this action again to return to its natural shape or adopt a new shape. Unless otherwise noted, a monster cannot use Change Shape to appear as a specific individual. Using Change Shape counts as creating a disguise for the Impersonate use of Deception. The monster's transformation automatically defeats Perception DCs to determine whether the creature is a member of the ancestry or creature type into which it transformed, and it gains a +4 status bonus to its Deception DC to prevent others from seeing through its disguise. Change Shape abilities specify what shapes the monster can adopt. The monster doesn't gain any special abilities of the new shape, only its physical form. For example, in each shape, it replaces its normal Speeds and Strikes, and might potentially change its senses or size. Any changes are listed in its stat block.

Extend Limb — The mezlan extends one of their limbs, granting themself a reach of 20 feet with their polymorphic appendages until the end of their next turn.

Viscous Trap — A creature hit by the mezlan's ooze globule takes a –15-foot circumstance penalty to all Speeds for 1 minute. On a critical hit, a target standing on a solid surface also becomes Immobilized, while a target Flying via wings falls to the ground and becomes unable to Fly.

A target can end all effects by Escaping or spending a total of 3 Interact actions to free itself.