There are very few items in Neopia that do nothing. The Lever of Doom is one of them.
Located in the supply deck of the Virtupets Space Station, the lever has a nice big DO NOT PULL sign over it. Of course, seeing this, you can't help but pull it. You will quickly find yourself 100 neopoints poorer, as it snatches 100 of your hard-earned NPs with every pull.
There is an avatar available from the lever. To earn it, simply pull on the lever until the 'Something Has Happened' event appears.
Note that this can be a very costly avatar, due to the fact that it is random. You may get it after 1 pull, or you may still not have it after 1,000 pulls.
Not enough NPs
If you have less than 100 NPs on you, you'll be happy to know that nothing will get stolen. However, you can not get the avatar this way. The NPs must be stolen for a chance at the avatar.