Once per friendly turn, at the start of any phase, Tretch can leave any unit he is with and make move of 2D6" as if it was the Remaining Moves phase.
Source: Warhammer Armies Project: Unofficial 9th Edition
Once per friendly turn, at the start of any phase, Tretch can leave any unit he is with and make move of 2D6" as if it was the Remaining Moves phase.