This is 100 Watton. It has the look of a red firefly-like lightbulb, and it controls the lights in Bright Man's stage. It will sometimes stop to shoot a missile from its tube that, when fallen onto any surface, explodes and separates into 5 sparks of electricity. Killing one will plunge the level into darkness until a Dompan is killed.
This 100 Watton was made not for battle, despite having its normal attack, but rather as a comfort companion and a messenger for Bright Man. When he sleeps with the 100 Watton, both of their sleep systems connect with each other, so that Bright can wake up immediately when it is taken away, and to have him be relaxed to where he doesn't need to turn on his lightbulb. When starting a recording, he will give a command for it to record his voice, the command being "Record please!" When stopping a recording, he will snap his fingers, and the Watton makes sure to not record the snap. Note that it will play like a cassette tape, having clicks to where a message starts and ends.
Watton can also speak, but it speaks in squeaks that only Bright can understand. It has its own tube on the ceiling of Bright's room so that it won't have to fly around all day or struggle with hopping on the floor instead.
Bright Man and 100 Watton do really connect together don't they?