Mine dragging refers to activating a Spider Mine from a long distance and then running into a cluster of Terran units. Mine dragging is most commonly seen in PvT matches, but is also fairly widespread in ZvT matches against mechanical builds.
A successful mine drag can deal spectacular damage and in televised games, it usually triggers commentators' hysteria. These latter shout "Mine Daebak !", which literally means "Huge damage dealt by a mine".
How to do it
Two units are most useful for dragging mines: Zealots and Dark Templar. Zealots usually do that when breaking a Terran push. Dark Templar have the advantage of being able to drag mines while there is no engagement, as the Terran units won't fire on them, but the mines will still activate.
One of the most common units for dragging mines for Zerg is Zergling due to its high speed. However, Zerglings are much weaker than Zealots so often multiple Zerglings will be used in mine dragging.
- BeSt vs. Upmagic (using Zealots) 
- Lucifer vs. Sheis (using Dark Templar) 
- Flash vs. GGPlay on Plasma (using Zerglings) 
- How you can toy around with mines