Knock-Knock

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

Characteristics
Knock-knock is a cleaner, more powerful version of the fire axe, with a matte black handle and a polished steel head with a longer fluke.

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.