Coagulated Tendrils

Inject a sample vial of blood with a small sample of slime biomass. When tossed, the solution spreads across a 10 ft. radius on the ground. All creatures within range (up to huge size) must make a dexterity saving throw against the spell DC or else crimson tendrils will bind the affected creatures in place (reducing movement speed to 0). At the beginning of each following turn, the creatures must succeed an athletics check against the spell DC to wrestle free from the tendrils. Creatures caught in the tendrils will take 1d4 acid damage at the beginning of each turn 1 minute.