Lava Bubble

Lava Bubbles, sometimes called Podoboos, Sparkies, Spark Spooks or simply Bubbles, are an enemy character from the  series.

Character description
Lava Bubbles (at the time, called "Podoboos") first appeared in Super Mario Bros., as fire balls that would jump out of the lava in simple patterns in an attempt to burn Mario or Luigi whenever the plumber tried to jump over them. In this game, they are invincible and not even a Super Star can defeat them, and only appear in Castles.

They are commonly depicted as a large fireball with two black eyes or also as only a large fireball. Lava Bubbles mainly appear in the Mario platformers but occasionally appear in several Mario sub-series, such as the Mario Party series, the Mario Kart series and the Paper Mario series.

In Super Smash Flash 2
In Super Smash Flash 2, the Lava Bubbles appearing Bowser's Castle as a background character. They jump in from the lava repeating at the same time as it goes for nothing.