All Termagants in units within 12" of the Tervigon have the Counter-attack special rule.
At the end of your Movement phase, a Tervigon can spawn Termagants, even if it is locked in close combat. If it does so, roll 3D6 - this is the number of models spawned. Place the new unit of Termagants on the table so that it is wholly within 6" of the Tervigon. Models in this new unit cannot be placed in impassable terrain or within 1" of enemy models. If you cannot place some of the models due to the restrictions above or because you have run out of Termagant models, the excess is discarded. The spawned unit cannot move during the Movement phase in which it is spawned, nor can it charge this turn, but it is free to shoot or Run as normal. A unit spawned by a Tervigon is identical in every way to a Termagant unit chosen from the Troops section of the army list, and is treated as such for all mission special rules. Models in a spawned unit are armed with fleshborers and may not purchase options. If any double is rolled when determining the size of a spawned unit, the Tervigon has temporarily exhausted its supply of larvae - the Termagant unit is created as normal, but the Tervigon cannot spawn any further units for the rest of the game.
Models with the Synapse Creature special rule have a synapse range of 12". Friendly Codex: Tyranids models within this synapse range, including the Synapse Creatures themselves, have the Fearless special rule. If a unit from Codex: Tyranids is falling back and at least one of the unit's models is within a friendly Synapse Creature's synapse range before the unit moves, the unit automatically Regroups.
All enemy units and models with the Psyker, Psychic Pilot or Brotherhood of Psykers special rules suffer a -3 penalty to their Leadership whilst they are within 12" of one or more models with the Shadow in the Warp special rule.
If a Tervigon is slain, roll 3D6 before removing the model as a casualty. Each friendly unit of Termagants within 12" of the Tervigon immediately suffers a number of Strength 3 APhits equal to the result. Cover saves may not be taken against these hits and Wounds are allocated as per shooting, with the Tervigon as the firer. After all Termagant casualties have been resolved (if any), remove the Tervigon from play.
Monstrous Creature
3
5
6
2
10
3+