Innertube Goomba

Innertube Goombas or Swim Ring Goombas are Goombas that use inner tubes (or floaties ) to drift and swim across the water. They first appear in Super Mario 3D World.

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, Innertube Goombas have spiky floaties. They 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 floaties appear.

Captain Toad: Treasure Tracker
Innertube Goombas 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 infinity pool on the rooftop of the buildings, only in the regular and R variants of the course. Their floaties protect them from inbound obstacles, bouncing away drivers, Green Shells and fireballs, while breaking Red Shells, Yoshi's Eggs, and Birdo's Eggs on contact. A Goomba and its floaty can be taken out by using an item such as a Super Horn or a Super Bell; by driving into one while boosting from a Mushroom or a Dash Panel; or by touching it while under the effects of a Frenzy, Super Star, Mega Mushroom, or Bullet Bill. When taken out, the Goomba and the floaty give points separately. Attacking a Goomba in a floaty with a Bob-omb takes out the Goomba while the floaty remains unaffected. A row of Goombas in floaties also appear in the Do Jump Boosts bonus challenge set on GCN Daisy Cruiser; here, it is shown that the floaties can be bounced off of for a Jump Boost, provided the player lands in-between the Goombas that wear them.

Floaties without Goombas appear in Singapore Speedway's Coin Rush mode. They lie on the sidelines of the pool section with coins in-between them, and the track's invisible delimitations prevent the player from interacting with them.

Mario Kart 8 Deluxe
Innertube Goombas appear in the Booster Course Pass for Mario Kart 8 Deluxe in. They can also be seen in Squeaky Clean Sprint, floating on a bathtub.