Gylou

Greater Darkvision — A creature with greater darkvision can see perfectly well in areas of darkness and dim light, though such vision is in black and white only. A creature with greater darkvision can see through even forms of magical darkness.

Telepathy 100 feet (aura, magical, mental) — A monster with telepathy can communicate mentally with any creatures within the listed radius, as long as they share a language. This doesn't give any special access to their thoughts, and communicates no more information than normal speech would.

Constant Spells — A constant spell affects the monster without the monster needing to cast it, and its duration is unlimited. If a constant spell gets counteracted, the monster can reactivate it by spending the normal spellcasting actions the spell requires.

+1 Status to All Saves vs. Magic —

Reflexive Grab —

Change Shape (concentrate, divine, polymorph) — 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.

Encage in Tentacles (attack) —

Indispensable Savvy — Frequency once per day

Trigger The gylou attempts a skill check but hasn't rolled yet

Effect The gylou demonstrates a preternatural ability for the task at hand. They use their Deception modifier for the triggering check and for all skill checks using the same skill thereafter until the next time the gylou uses this ability or until 24 hours have passed, whichever happens first.

Grab —