Sentry Beam

Laser Robots are metallic robots that make their only appearance in Super Mario Galaxy and its sequel Super Mario Galaxy 2 as enemies who try to defeat Mario by firing lasers at him.

Super Mario Galaxy
Laser Robots first appear in Flipswitch Galaxy and re-appear in Battlerock Galaxy, Bowser Jr.'s Airship Armada, Toy Time Galaxy and Flipswitch Galaxy.

Super Mario Galaxy 2
In Super Mario Galaxy 2, they appear in a few galaxies, namely Mario Squared Galaxy and Grandmaster Galaxy.

Traits and Abilities
Laser Robots are purple in appearance and somewhat resemble Topmen, they constantly remain stationary and attack by firing lasers in a circular ray-like shock wave and if they hit Mario he will lose one health. Laser Robots constantly fire out circular ray-lasers whether Mario is near or not and the lasers have a limit as to how far they can go before they disappear. They cannot be destroyed under any circumstance, however there is a way to stun the robots, impairing them for several seconds and giving Mario refuge from their barrage of attacks. If Mario either jumps on top of the robot or fires a Star Bit at it then the robot will become stunned and the spring beneath its head becomes exposed and Mario can then use them like a trampoline. Some of these purple robots do not fire laser, but still have a springy neck.

There are also very rare types of Laser Robot, one has a nut on top of it, while one has a bolt. They're both found in Buoy Base Galaxy in Super Mario Galaxy on the Poké Ball Planet, with the nut-like robot on the bottom of the planet and the bolt-like robot on the top. The Laser Robot with the nut is like the original purple robot with no springy neck, but once Mario or Luigi spins on the bolt of the bolt Laser Robot, the planet opens up to reveal the Power Star.

Laser Robots also have a spiked yellow variant which attacks in the same way as its purple counterpart, but due to its spikes Mario cannot stun it, they also lack eyes.

The final variant of Laser Robot is a gray, undefeatable, mobile unit with sinister-looking eyes, which hovers around with the aid of a propeller at its bottom. This variant can shoot a straight laser beam at Mario from its mouth that is very fast and very hard to dodge. If Mario stands on its head it will cease all action but once Mario starts moving again it will continue with its attack.

All Laser Robots are invincible, they cannot be defeated by anything less than Rainbow Mario himself. Mario can throw Bob-ombs at the robots but they will still not be destroyed and will resume their attack momentarily.