Robo is an enemy in Dig Dug Arrangment. They are brown robots who will explode if you pump them up. This is an easy way to kill enemies if you run out of rocks. but be aware if you are to close the explosion you will die too.
Staying Safe
Keep your distance when killing Robos. Be as far as posible and then pump, but if one if right next to you pump it once and then walk away and then pump.