Well, there are really three likely possibilities for what it is:
It's a needlefish a.k.a. true needlenose gar. These are not true gars; they are of the family Belonidae.
It's a pike characin; these are commonly mislabeled as "needlenose gar." Once again, these are not true gar; they are of the family Ctenoluciidae.
It's a longnose gar; these are sometimes referred to as "needlenose gar." Of the three listed fishes, these are the only true gars; they are of the family Lepisosteidae.
Odds are it falls into #1 or #2. If it does, then this thread is in the wrong section. It should be in "Other Monster Fish" for #1 and in "Other Characins" for #2.
If it is actually a longnose gar or some other true gar (#3), then you're in the right place!
Guys, I'm pretty sure liljag meant the Xenentodon cancila needle nosed gar (sorry if i'm wrong). they are the amazon specis a false gar. They have a needle like mouth and they can grow to a max of around 12 inches or not even. they are a surface dweller and a quite peaceful. their needle mouth is delicate so you should have ur tank planted with plants so cushion a bang on the glass. You'll need at least a 30 gal (50 gallon would be alot better) to house one fish.