Gnasher Dashers make Supporting Attacks instead of their Cave Goblin riders.
Gnasher Dashers gain Impact Hits with the following exception from the normal rules: instead of causing one Impact Hit per (charging) Gnasher Dasher model in base contact with an enemy model, the (charging) Gnasher Dasher unit causes D3 Impact Hits for each 5 Gnasher Dashers in the unit, rounding fractions up, to a single enemy unit in base contact with the unit. For example, a unit of 1 to 5 Gnashers Dashers would inflict D3 Impact Hits, while a unit of 6 to 10 Gnasher Dashers would inflict 2D3 Impact Hits.