In Mother 3, Yokuba (known as Fassad in the fan translation) was the traitor among the Magypsies whose real name was Locria. He told Porky Minch about the Nowhere Islands and the Seven Needles. He corrupted Tazmily Village along with the villagers, and attempted to kill Lucas (Mother) and his friends but ended up falling off of Thunder Tower. He was then reconstructed into a powerful foe and attempted to track down Lucas again for a rematch. He was defeated when his jetpack failed him after taking too much damage, and he plummeted to the bottom of a sewer.
Fassad was not always known by that name. He had another name which he cannot recall. Back when that name was his, he was a spy sent in by an opposing nation that wanted to pinpoint the location of the Three-Mile Island base. He managed to become the protector of the secret switch beneath that island, and sent the coordinates to his employers. When Three-Mile Island was struck, he managed to escape the base where the switch was hidden, but could not get off the island in time. The strike left none remaining- except for him (possibly due to his exposure to the switch.) However, when he awoke weeks later, he had forgotten everything about his past life, and his prolonged time spent on the seething atomic wasteland of the island had mysteriously granted him the most concentrated and dangerous PSI abilities. He was unaware of this, though. After wandering for an unprecedented amount of time on the island, he felt starved and made a makeshift raft to get to another island. It turned out to be the most barren of the islands, Mystery Island, with nothing to eat but Blue Pineapples. So, he ate nothing but these pineapples, and for many years he wandered lost in the Desert of the Blue Pineapple. The amount of PSI in his body strengthened his connection to the switch, keeping him tied into existence. When the Pig Army arrived, he introduced himself as Fassad, the name that the Desert of the Blue Pineapple had given him. Porky Minch sensed his PSI overdose and welcomed him into the army, revealing his glorious scheme to take over the islands.
Porky already knew about the switches for many years, having traveled to every time in the past. He kept the secrets to himself.