Mouse

Along with Luke Skywalker, Basso, Able, Deena Shan and other Rebels, they conducted an infiltration of The Kalist VI Imperial Base, eight months after The Battle Of Yavin. 
 
For the conclusion of the mission, Mouse was in charge of creating diversions via planting explosives around the base. However, whilst putting them in place Mouse was discovered by Imperial Troopers who were extremely wary and suspicious of what he was doing, they ordered him to take off his helmet. And as they stod staring at him dumbstruck, he made a run for it towards the maintenance tunnels. Despite the troopers finding him and gunning him down, Mouse was sill able to trigger some of the diversionary explosives, something which secured success of his companions.