Knock-Knock

 is a unique weapon in Fallout: New Vegas. It is a unique variant of the fire axe.

Characteristics
This weapon differs from the standard fire axe in both physical appearance and in colour scheme. The axe head has a longer and thinner fluke and has a chrome head with a matte black handle. Knock-Knock has a special move (50 Melee Weapons) in V.A.T.S. called Mauler, which can knock enemies down, but costs significantly more action points. Mauler will sometimes knock a weapon out of an enemies hand instead of knocking them down.

Variants

 * Fire axe

Location
It is found in Camp Searchlight's Fire Station. Once you get the key from Logan, head upstairs and search the bathroom stalls, look in the right side corner of the stall with the skeleton to find the Knock Knock.
 * You can kill Logan, or you can complete the quest Wheel of Fortune to get the key.