Dark Matter

One target that you can see must make a Strength saving throw. On a failed saving throw, the target's movement speed is reduced by 20 feet until the start of your next turn, as a shadowy liquid soaks their body and begins to drip from their limbs. This spell only effects creatures that are large or smaller and has no effect on incorporeal targets. Tiny creatures who fail their saving throw and creatures whose movement speed is reduced to 0 are restrained. A creature may use an action on their turn to make another Strength saving throw, ending the effect early. When a creature teleports to a different location, they are no longer affected by the spell.