Drill Lurker is a Gene Tonic in BioShock 2. It decreases the sound of the player's footsteps and increases melee damage against unaware enemies. An even greater damage bonus is applied when the player is using the Drill. This tonic has a similar effect to the Wrench Lurker tonic from BioShock.
Found in a Vacuum Bot (among a single shoe) in a sideroom past the Executive Wing's Mag-lock door, in Minerva's Den (Level). Can also be purchased for 50 ADAM in Gatherer's Gardens onward the first machine in Operations.