In the original Rayman game, yellow lasers can be seen being shot from Space Mama's rolling pin in her second encounter with Rayman. They also appear in the second part of the battle with Mr Dark, when he is morphed into two smaller versions of Space Mama and Bzzit.
In Rayman 2
In Rayman 2, lasers are mostly seen in Robo-Pirate bases. They are either stationary or move in a set pattern. Most of them are there to prevent the player from reaching a certain area, while others act as obstacles. When Rayman comes into contact with a laser he will take damage and sometimes die instantly.
Lasers in the PlayStation version of Rayman 2.
The lasers are keeping Carmen the Whale trapped, as seen in the PlayStation version.
In Rayman M, Rayman Arena and Rayman Rush, lasers appear in the race levels Thousand Waterfalls and Zenith Harbour. When touched, the player will be stunned for a few seconds before being able to continue.
In Rayman 3
At the beginning of the first section of Clearleaf Forest there is a room with a floor covered with lasers. The player must avoid them by climbing above them. If touched, they make Rayman loose health quickly.
In Rayman Legends and its spin-offs
In Rayman Legends, lasers appear in 20,000 Lums Under the Sea. The lasers are all red. They are connected to a Dark Sentry which will fire at the player when touching the laser. If the player finished the level Mansion of the Deep without touching any lasers, the trophy Splinter Ray is earned.