Goombrat

Goombrats are a species of Goomba that debuted in New Super Mario Bros. U. The enemy's name is a portmanteau of "Goomba" and "brat". They are short, lighter brown, and resemble persimmons more than mushrooms. They have wider eyes in a scowl instead of eyebrows, and the black stems on their head are similar to tomato leaves. They also turn when they reach edges, which is similar in behavior to the red Koopa Troopas. Additionally, their teeth point down and have a curved shape, while regular Goombas' teeth point up and are sharp. The teeth look similar to how Goomba teeth do in Super Mario Bros. 3.

New Super Mario Bros. U
Goombrats debut in New Super Mario Bros. U. They only appear in Mushroom Heights, and one of the levels in Challenge Mode, The Goombrat Stomp.

New Super Luigi U
In New Super Luigi U they are significantly more common.

Super Mario Run
Goombrats appear in the version 3.0.4 update in Super Mario Run, where they appear in the levels Scuttlebug Forest and Spike Bar Jungle. In Scuttlebug Forest, one can be seen with a Super Mushroom on its head. A few other Goombrats glow in a yellow tone, and stomping them will release more coins than usual. A large variety also appears in some special remix courses in the Remix 10 mode.

Super Mario Maker 2
Goombrats appear in Super Mario Maker 2, as a variation of a Goomba.

In the Super Mario World style, similar to how Goombas are replaced by Galoombas, Goombuds are a new enemy that appear similar to the Goombrat but are able to be knocked over and carried instead of stomped on.

Mario Party series
Goombrats reappear Mario Party 10, seen in some minigames alongside Goombas and Galoombas. They also appear in Mario Party: Star Rush.

Super Mario Run

 * Notebook bio: "This enemy enjoys going for strolls in the forest. Vault over it, or just give it a good ol' stomp!"