Bumpety Bombs (コロコロ爆弾, Roly-Poly Bombs) are enemies from the Kid Icarus series.
In Super Smash Bros. 3DS/Wii U
Bumpety Bombs appear as enemies in Smash Run.
Upon spotting the player, an exclamation point will appear over them, and they will rush towards the player and attempt to detonate themselves. The time it takes for them to explode varies; it can be almost immediately or very late. Attacks from behind or simply grabbing them is the easiest way to dispose of them. They explode upon death (or if they detonate themselves), which also hurts nearby enemies.
This pesky bomb has wheels, which means the time-tested strategy of running away doesn't work as well as you'd hope. Be ready for a big blast if this bomb hits zero. Oh, and sometimes the fuse is a little shorter than normal. You'll have to attack from behind to defuse this dangerous foe.