Area 20-foot burst adjacent to a flat surface
Oily black tentacles rise up and attempt to capture creatures in the area. Make spell attack rolls against the Fortitude DC of each creature in the area. Any creature you succeed against is Grabbed and takes 3d6 bludgeoning damage. Whenever a creature ends its turn in the area, the tentacles attempt to grab that creature if they haven't already, and they deal 1d6 bludgeoning damage to any creature already Grabbed.
The tentacles' Escape DC is equal to your spell DC. A creature can attack a tentacle in an attempt to release its grip. Its AC is equal to your spell DC, and it is destroyed if it takes 12 or more damage. Even if destroyed, additional tentacles continue to grow in the area until the duration ends. You can Dismiss the spell.
Traits
An ability with this trait involves an attack. For each attack you make beyond the first on your turn, you take a multiple attack penalty.
An action with this trait requires a degree of mental concentration and discipline.
You must physically manipulate an item or make gestures to use an action with this trait. Creatures without a suitable appendage can't perform actions with this trait. Manipulate actions often trigger reactions.