Wazer Wifle (Fallout 3)

The Wazer Wifle is a unique version of the AER9 Laser Rifle. It may be purchased in Little Lamplight from a child named Biwwy for 500 caps, or received freely through dialogue if you have the Child at Heart perk. If your barter skill is high enough (atleast 50) you can get it for 250 caps. Biwwy stands near the back of the Great Chamber. This weapon looks exactly the same as the regular laser rifle, but does a bit more damage, and also sports a larger magazine at 30 rounds instead of the regular 24. It is received in near-perfect condition. It may be repaired using the standard AER9 Laser Rifle.

Its name is written as a child without completely developed speech skills, thus pronouncing all L's as W's.

The Wazer Wifle is also a very hardy weapon and can go a long, long time without needing repairs. This makes it a good weapon for those with low repair skill.

Hoax
There are rumors that Dogmeat can use this weapon. However, nobody ever got it working or proven with a save game, so it's more or less consensus that the image is a fake.
 * The thread that started it at somethingawful.com, with a picture (named shhhthisisajoke, to prove the fact).