On defense, place Giant Skeleton in the middle of a big enemy push; the bomb it drops clears the support troops. On offense, if it gets close to the tower, the bomb deals huge tower damage. Opponents usually try to kill it far from their tower.
Tips
Placed in the middle of swarms, the bomb wipes them all.
On offense, use a small spell to clear the way so the bomb lands on the tower.
Watch out for Tornado, which can pull the bomb back to your side.
Strengths
The bomb it drops on death hurts defenses and towers.
High health makes it a good tank.
Weaknesses
Slow single-target damage; struggles against tank killers.