The Blaster (called Blaster Shot in Super Smash Bros.) is Fox's Neutral B special move in all three of his incarnations in the Smash Bros. games, which is shooting a laser gun to damage faraway opponents. In SSB, the Blaster shoots a pink laser beam that travels slower than a standard Ray Gun shot, does some damage, and has a little knockback. The Blaster has increased fire rate while Fox is airborne. In SSBM, however, Fox's Blaster is quite different: its rate of fire and traveling speed is drastically increased, has absolutely no knockback, and does 1%-3% damage per blast. This is one of the few moves in the game that can never, under any circumstances, provide a KO, except for stealing other players' KO's. It is mainly used from long range to help build damage for later KO attempts and the Home-Run Contest. In SSBB, Fox's Blaster has once again changed: the range of the Blaster now travels roughly half of its previous distance, and he cannot cancel the lag of putting his Blaster away simply by landing. Positive changes have also been made, however. His blaster now inflicts an average of 2%-3% per shot, with 3% being more likely at close range and 2% at a longer distance. This is much more efficient at quickly inducing damage. Fox is also now capable of a short hop triple laser, allowing him to inflict more damage on opponents who are falling to the stage. Ever since SSBM, Fox's Blaster has been capable of shooting rapid, mulit-fire lasers, instead of the single, long, pink beam from the original game.
Fox's counterpart, Falco, also has this move, but his Blaster is a bit different. Falco's Blaster attack more closely resembles the old Fox's Blaster attack from SSB.
Fox has been pictured with a gun since Star Fox 64, but it hasn't been until Star Fox Assault (excluding the original Super Smash Bros.) that Fox would actually use one (in Star Fox 64, if the ability to play as the pilot on-foot in multiplayer was unlocked, he would use a Rocket Launcher). His basic Blaster has unlimited ammo, and is capable of charging a rather powerful Charge Shot. In lieu of high powered weapons like a Rocket Launcher, a fully charged Blaster shot would be the only thing Fox had to damage enemies with shielding.
The Blaster is Falco's Neutral B special move in his Melee incarnation, which is shooting a laser gun to damage faraway opponents. It is similar to Fox's, but has its differences: the Blaster has a slower firing rate, though it fires faster in the air, but not as fast as Fox's, and each beam stuns the opponent in addition to doing damage. It is mainly used from long range to help build damage for later KO attempts, and as an aid in approaching. Falco's Blaster in SSBM closely resembles Fox's Blaster as it appeared in the original Smash Bros.
In Brawl, the beams from Falco's Blaster travel farther than the beams from Fox's, and they are blue instead of red.
A small glitch with Falco's Blaster is that if used at the right range, it will stick into some platforms and remain damaging until it expires. It can most easily be done on New Pork City (or any custom stage with a specific type of ramp), when you stand where the bridge begins and fire at the platform to the left. It can also be done in Brawl's Hyrule Temple, on the ramp to the far upper-right of the stage, if you stand in a certain spot and fire.
Also, this is not a glitch, per se, but characters can become trapped in a tumble animation, called Laser Lock, if hit repeatedly with Falco's Blaster just before they hit the ground while free-falling.
The Blaster is Wolf's Neutral B special move in Super Smash Bros Brawl (in Japanese, the move is called "Claw Blaster" クローブラスター). The beams are colored green. It has the slowest firing rate, and is shorter ranged than Fox's or Falco's Blaster. However, it is stronger than the two (normally doing 5-8% damage), and has decent stun and knockback. A bayonnet is attached on Wolf's Blaster, thus dealing 5% added damage when the attack is done at close range, even having the potential to KO, which no other Blaster can do. But he can't fire continuously, as he draws and holsters it for each shot, similar to how the fastest Charge Shot works.