Cobra by Timothy Zahn (Cobra Trilogy, Book 1)

   A sudden rustle of cloth brought Jonny's attention back to the priest. The service was drawing to a close, he saw, and the crowd was kneeling for the final prayer. Hastily, Jonny dropped to his knees, glancing around as he did so. Challinor's Cobras were still on their feet, whatever feelings of respect they might have overridden by the tactical necessity of keeping close watch on the crowd. Out of the corner of his eye he saw Almo hesitate and then, with a glance in Jonny's direction, kneel with the rest of the people around him. Between the coffin stands Father Vitkauskas had himself knelt . . . and as he began the requiescat, Jonny's eyes sought Chrys, saw her hand slip under the hem of her long skirt to the device strapped to her leg . . . .
   And MacDonald sat up in his coffin.

MacDonald sits up in his coffin . . . and subsequently unleashes a wild spray of laser beams into the unsuspecting Cobra rebels. YESSS.