Selim Wormrider (218 BG - 174 BG) was a Zensunni orphan grown on the planet Arrakis. Expelled from his tribe, he survived on the desert and was the first person to manage to ride sandworms. He formed an outlaw band and eventually founded the Fremen.
Selim was born in Naib Dhartha's tribe and became an orphan at a young age. As a toddler, Selim had been raised by different persons, none of whom had adopted him as part of their family. Glyffa was the only one who helped him like a mother to him and was childhood friends with another boy, Ebrahim.
He had always been an impulsive and energetic boy. He was skilled at throwing rocks and could pick off ravens, kangaroo mice, or lizards for the community cookpot. Because of his unknown parentage, the tribe demanded more work than most others and the others' behaviour was unjust. Once, he had accidentally spilled an entire day's ration of water and he was denied by fluids for two days, although he was the only one to have suffered this punishment. Another time, he noticed that after he was lost in the desert for two days, none of this tribemen noticed his absence.
One day Ebrahim found an unattended literjon of water and drank it, something that was considered a very important crime among the Zensunni tribes of Arrakis, since water was scarce and vital. The shame would be very grave if he was accused. It was decided between his father and Dhartha that it would be better if the blame would go on an orphan, Selim. Selim was expelled from the sietch as a water stealer.
Selim was humiliated and condemned and with a steel walking stick and some rocks, left the sietch and wandered on the desert. Eventually he detected an approaching sandworm. Feeling doomed, he decided not to run, but desperately attack. As the worm lifted itself from beneath the dunes, Selim leaped onto its back and plunged the sharpened tip of his stick. To his surprise, the stick slipped between segments, into soft pink flesh.
The worm reared up, thrashed, and writhed. He observed that the worm raced forward, keeping itself high out of the sand where the exposed tissue would not be abraded by it. He then realized that he actually rode the worm. Selim held on the stick, fearing that if he let it, the worm would dive again in the sand and drown him. For a day and night he stayed there and the beast eventually dropped dead of exhaustion. After reassuring that it was dead, Selim unrooted one of his fangs.
Nearby, Selim discovered an ancient botanical testing station camouflaged in the rocks, assembled by Old Imperial scientists who studied the environment of Arrakis. The camp gave him shelter, as well as the ancient rations that stayed there preserved. He also found hundreds of literjons of water, collected over the centuries by automated moisture extractors.
Being a loner, he started raiding his village, as well as making his presence noticeable, insulting and challenging Dhartha. One time, he saw a batch of his tribemen gathering melange, to sell it to offworlders.
One night, after consuming a large amount of melange, he saw a vision; the process of the melange creation, the sandworms' relationship to it, and the disastrous effects should they lack melange. Selim realized that Buddallah wanted him to protect the sandworms (which he recognized as Shai-Hulud) and the planet.
Selim started to form his own band; he saved the life of a lost man, whose name was Jafar, who became his right hand later, when his band grew. The team of Wormriders followed Selim and sabotaged Dhartha's harvesting teams who gathered spice. They became a grave problem to VenKee Enterprises, who held the commercial rights of spice, disrupting the normal process of the spice market. Selim ever welcomed new members, and all were trained in worm-riding. He eventually welcomed Marha, a girl that came from his own village. She later became his wife.
Selim's legend grew and even Dhartha's grandson, Aziz admired him, witnessing his band stealing recently gathered spice from a harvesting band, and spilling it back to the desert. Aziz met him personally sent by Dhartha, in an attempt of reconciliation, but Selim sent him back.
Aziz was still obsessed with Selim and really wanted to make his grandfather and his hero friends. He attempted to lure and ride a sandworm and impress Selim. During this attempt however, he was devoured, witnessed by Dhartha, who then vowed to destroy Selim.
VenKee Enterprizes were much worried by the outlaws. When Aurelius Venport visited Arrakis to investigate, Dhartha told that he would need military forces to encounter Selim. Dhartha had found already kanla followers and Venport gave him mercenaries; the team, guided by Dhartha, arrived at the outlaws caves. The melange however 'told' Selim about the imminent assault and ordered all his people moved elsewhere the previous night.
Selim stayed alone to see the intruders. Only having a drum, he started hitting it summoning the worms. Two worms came and devoured the mercenaries, even the flyer who attempted to escape. A third worm ate Dhartha's followers while he ran towards Selim. When the two men were left alone, and Dhartha cursed and threatened his rival, a fourth one opened its mouth right below them.