Bulber

Bulbers are anglerfish-like enemies that first appear in New Super Mario Bros. Wii. Like real anglerfish, their bulbs illuminate any darkness around them, similarly to Jellybeams.

New Super Mario Bros. Wii
In New Super Mario Bros. Wii, Bulbers only appear in World 8-4. They swim freely in the water, illuminating the area around them. They can be defeated by attacking them with a fireball, by freezing them, or by running into them with a Star, although this is not necessary and perhaps even detrimental due to loss of illumination. Bulbers are passive, hurting Mario only if he touches them.

New Super Mario Bros. U
Bulbers reappear in New Super Mario Bros. U where they act exactly as they did in New Super Mario Bros. Wii, appearing alongside Jellybeams in Deepsea Ruins of Soda Jungle. They do not reappear in New Super Luigi U.

Mario Kart Arcade GP DX
Although Bulbers are absent from Mario Kart Arcade GP DX, there exists model data for one in the game files.

Mario Kart Tour
In Mario Kart Tour, two Bulbers appear in Piranha Plant Cove and Piranha Plant Cove 2, above the pillars of the first route's starting line.