Minvos (ミンボー Minbō) are enemies in the Bomberman series. They move like fast Onils, and resemble smiley faces. These are encountered after the Dahls. They will commonly pursue Bomberman if he's nearby, though they do also get stuck if he's hiding nearby.
Minvos are quite easy to beat, just treat them like Onils, only you have to be quicker in getting it out. Since they're encountered after the Dahls (encountered on the third stage), you have probably got the Remote Bomb, so it will be a bit easier. Just evade the Bombs, though!