Rilldo first appeared when another villain, Dolltaki, came to Planet M-2 with two of the Dragon Balls after his defeat at the hands of Goku, Trunks, and Pan. However Rilldo destroyed Dolltaki because of his failure.
Later when Goku, Trunks, and Pan came to planet M-2, RIldo sent the elite Sigma Force to capture them. After they were destroyed, he went to take care of things himself. Rildo managed to trap Trunks using his mouth beam that can turn things into metal.
He was however defeated by Goku and quickly powered up by transforming into Meta Rilldo, using parts from the defeated Sigma Force. Goku was forced to transform into a Super Saiyan and after awhile, began to gain the upper hand. Rilldo transformed again into Hyper Meta Rilldo, which gave him the ability to fuse with any metal on the planet. Later Goku, Pan, and Trunks attempted to leave the planet, only for Rilldo to grab their ship. Trunks told him that he was only a pawn to Dr. Myuu and that as soon as Baby was finished he would have likley been deactivated. Rilldo didn't listen to this and he was destroyed by a Kamehameha wave from all three of them.
Like all the other villains, Rilldo made an escape from Hell during the Super 17 saga. He first attacked Pan and Mr. Satan, but Gohan showed up and fought him instead. Rilldo managed to gain the upper hand by encasing his arm and leg in metal. Just as he was about to strike the killing blow, Rilldo was destroyed by Majuub.
Rilldo possesses superhuman abilities, since he is a machine and the ability to manipulate energy, just like most of the other characters in the various Dragon Ball series. He also has an ability called Metal Breath, which is a green beam fired out of his mouth, that encases whatever it hits in metal. This attack can also spread to affect more of an area as seen in the Super 17 saga. Rilldo can also transform like numerous villains in Dragon Ball Z and Dragon Ball GT. He uses his first form to hide his true power, while he uses his other forms for serious battles.
- Rildo is very similar to Dabura in their history and attitudes toward their masters. Dabura's Stone Spit attack is also very similar to his Metal Breath attack.
- Rildo states that Goku would be like him if he ever became a Machine Mutant. This suggests that Rildo was an organic being at one point.
- In his Hyper Meta form, Rildo bears a resemblance to Cooler after he became Meta-Cooler. Interestingly, the two also had the same voice actor.