Innertube Goomba

Goombas on spiky swim rings first appear in Super Mario 3D World. They use the rings to drift and swim across the water.

Super Mario 3D World / Super Mario 3D World + Bowser's Fury
In Super Mario 3D World and its Nintendo Switch port Super Mario 3D World + Bowser's Fury, swim ring Goombas first appear in the level Pipeline Lagoon, and are also seen in Sprawling Savanna Rabbit Run. Normally, they are sleeping peacefully in the water, but if the player gets close, they wake up and paddle towards the player, damaging them if they touch them. They can be defeated with any attack.

In the Bowser's Fury campaign of Super Mario 3D World + Bowser's Fury, Cat Goombas riding on swim rings appear.

Captain Toad: Treasure Tracker
Goombas on swim rings return in Captain Toad: Treasure Tracker, appearing in water levels such as Floaty Fun Water Park and Goomba Galleon. They behave the same as in Super Mario 3D World.

Mario Kart Tour
Goombas on floaties make their Mario Kart series debut in the Singapore Speedway course from Mario Kart Tour. They appear in the rooftop pool section in the regular and R variants of the course. Their floaties protect them from incoming obstacles, bouncing away drivers and Green Shells, and breaking Red Shells on contact. A Goomba in a floaty can be taken out using an item such as a Bob-omb or a Super Horn, or by driving into one while invincible or under the effects of a Mega Mushroom. When taken out, the Goomba and the floaty give points separately.