For the allied unit in Siege mode, see Sapper (Siege).
Sapper battle
Faction Clockworks
Source 1000
Health 1049 (easy), 1500 (normal), 1875 (hard)
Damage 13 (easy), 20 (normal), 25 (hard)
Ability Burrows underground
First encountered Day 30, Deception Pass

The Sapper is a boss Clockwork modelled after the Clockwork Burrower that plants explosives on the walls at the end of each day at Deception Pass, pushing back Kingdom Force and forcing Lock to rebuild the walls. Its battle is different from than most battles. Kingdom Force knights set up a trap to catch the Sapper, and Lock must defeat it before it escapes. The day is lost if Lock is defeated or the Sapper escapes off-screen. The day is won when the Sapper is defeated.

PainSapperHeavyPhantom RingleaderBeastMuteWar MachineLord AgonyKenan

Silver SoldierSilver ArcherSilver KnightSilver BruteSilver ShielderSilver BurrowerSilver HealerSilver FlyerSilver Phantom
Elite SoldierElite ArcherElite KnightElite BruteElite ShielderElite BurrowerElite MagicianElite HealerElite Flyer
Elite Phantom
Bosses: PainSapperHeavyPhantom RingleaderBeastMuteWar Machine