Overwhelm: the Goblin hoard tries to bury its enemies underneath itself and drown them in its blood and dead always trying everything they can to bite, kick and claw its pray, they form a tidal wave of goblins as they all try to climb over each other and get to there pray first. Once prey is captured it is knocked prone and must try to either stand up or crawl away; the dm decides the dc for standing up as it depends on the number of goblins on top of you. On each of your turns, you take (1d2 slashing damage, 1d2 piercing damage and 5d12 bludgeoning damage and if more then 50 goblins have died within 20 feet of you, you start to suffocate in their blood) the goblin hoard does the same to everyone it has captured including itself on each of its turns. moving inside a goblin hoard is considered difficult terrain.   reinforcements, if the party is within five miles of any of the following: Goblin hill Goblin Cave Goblin tunnels Goblin mountain then on each of the Goblin hoards turns it will add (1D100 for hill, 3D100 for cave, 5D100 for tunnels, 12D100 for mountain) Goblins to its mass unless the previous have been blocked off sufficiently.