This black, viscous goo feeds on Underdark insects and vermin by trapping them in place and slowly digesting them. This black, viscous goo feeds on Underdark insects and vermin by trapping them in place and slowly digesting them.
Effect: Grasping slime is difficult terrain. A creature moving through a square of grasping slime must make an Athletics check (based on the creature’s level) to pass. On a failed check, the creature ends its movement in that square.
Usage: Use multiple patches of grasping slime to slow the characters’ advance against ranged creatures, potentially giving those creatures multiple rounds to attack. The slime’s ability to negate movement will also give soldiers with marking powers time to engage the front ranks of stuck characters, further slowing their advance while the ranged creatures continue to attack. Grasping slime is also a good way to control the characters’ movements, funneling them toward a trap.
Published in Dungeon Master's Guide, page(s) 68.