Gloomba

Gloombas are navy blue Goombas that appear in the Paper Mario series. Gloombas live deep underground, and are much more powerful than their surface-dwelling cousins. The coloration of Gloombas resembles that of the Goombas found in underground levels in Super Mario Bros. and Super Mario Bros.: The Lost Levels (especially their appearance in the Super Mario All-Stars versions of both games), while their name is a portmanteau of "gloom" and "Goomba."

Paper Mario
In Paper Mario, Gloombas appear solely in Toad Town Tunnels, where they are the most basic enemy. Like normal Goombas, they are weak to every type of attack, but are much more durable than them. They appear alongside Paragloombas and Spiked Gloombas.

Paper Mario: The Thousand-Year Door
In Paper Mario: The Thousand-Year Door, Gloombas now inhabit the early floors of the Pit of 100 Trials along with their subtypes. This game reveals that Gloombas' coloration is a result of not getting any sunlight. They act effectively the same as before, but are slightly stronger.

Super Paper Mario
In Super Paper Mario, Gloombas initially appear in the underground portion of World 3-1, The Bitlands, where they stand in for the blue Goombas from Super Mario Bros. Later, they appear in Castle Bleck Foyer and the Flipside Pit of 100 Trials. Their subtypes are not present in this game. In the Prima strategy guide, it is stated that Gloombas can poison the player, though this is false.