Embodiments of the present disclosure are directed to apparatuses, devices, and methods for locks for endoscopic accessories. In one implementation, an adjustable lock for an endoscopic accessory includes a body slidably mounted upon a rail of the endoscopic accessory, and an arm extending about a portion of the body. The arm may be connected to the body and pivotable relative to the body between a closed position and an open position. In the closed position, teeth on an inner surface of the arm may engage a toothed rack on the rail such that the adjustable lock is secured to the rail. In the open position, the teeth on the inner surface of the arm may be clear of the toothed rack such that the lock may slide relative to the rail.