Beneath the mountains of Parsis (Par-SIS), you discovered a large stone covered in glowing runes trapping someone behind it — a Frogkin woman with smooth white skin, eyes as black as tar. - Festival of Heroes (GS-ADV1)

The Frogkin god of nightmares.

Yalaka was imprisoned long ago by [ ] for her misdeeds and transgressions against [ ].

Yalaka appears to delight in driving mortals insane;

She smiles, knowing that her visions are slowly chipping away your sanity. - The Hive (GS-ADV3)

Yalaka visits those she torments in their dreams, forcing them to live countless nightmares and visions in their non-waking hours;

You pushed the stone aside and she smiled at you, opening her mouth to unleash a swarm of locusts. Then, she disappeared in a cloud of smoke. Ever since, you’ve been haunted by horrible nightmares — giant frogs chasing you through the streets of Wildwood; rusted Constructs feasting on Human flesh — and through it all, the pale Frogkin woman always appears, the source of your fearful visions. - Festival of Heroes (GS-ADV1)

A statue to Yalaka occupies the Temple of Shintal in Wildwood;

Beside the altar to Shintal rest many statues to lesser gods. To your horror, you realize that one of them is of the Frogkin woman you released from the mines. The statue’s base reads, “Yalaka (yah-LAH-kuh), Frogkin goddess of nightmares.”

It seems you have released no ordinary spirit, but a god of chaos and disorder. - Festival of Heroes (GS-ADV1)