Wander is the lone player character in Shadow of the Colossus. He is a young warrior with shoulder-length hair who wears simple clothing and a tabard bearing a distinctive sigil-like pattern. During the course of the game, Wander carries a bow and an ancient sword with magical properties necessary to complete his quest. Wander rarely speaks; his few lines of dialogue are spoken in a fictional language to address either his horse Agro or the entity known as Dormin.
The game begins with Wander approaching the Forbidden Land on horseback. After crossing the great stone bridge leading into the Shrine of Worship, he and Agro enter the Shrine and descend into its main cathedral-like chamber. Wander dismounts and gently places the body of Mono onto the Shrine's altar. A group of shadowy creatures suddenly manifest to attack Wander and Agro, but he easily dispatches the phantoms simply by holding his ancient sword aloft.
After clearing away the enemies, the disembodied voice of Dormin speaks to Wander directly and expresses surprise that the young warrior possesses such a powerful artifact. Wander explains that he has come to the Forbidden Land to beg Dormin's aid in resurrecting Mono. Although Dormin laughs at the mortal's odd request, he informs the human that such a feat may be possible if Wander can defeat the sixteen Colossi who roam the Forbidden Land.
Despite Dormin's warning that the price for restoring Mono's soul may be steep, Wander immediately sets out from the Shrine and defeats each of the Colossi in turn, aided only by his faithful steed Agro. With each Colossi that falls, Wander's appearance becomes more corrupted; his skin becomes paler, his hair grows darker, black veins appear across his face and a pair of small horns begin growing out of his head. As Wander's appearance deteriorates, Mono's condition seems to improve, and her voice is briefly audible after the vanquishing of each Colossus. After the fall of the Twelfth Colossus, Dormin informs Wander that he must hurry to complete his quest, as he is being pursued by the shaman Lord Emon and his followers.
Upon traveling to the location of the Sixteenth and final Colossus, Wander watches his horse Agro sacrifice herself by throwing Wander to safety when he tries to ride Agro across an unstable bridge. As a result, Wander faces the final Colossus alone. Lord Emon and his company arrive at the Shrine of Worship just in time to witness the last of the Shrine's stone Colossi effigies collapse. Wander reappears inside the shrine shortly after, his visage now so twisted as to be nearly unrecognizable. Announcing that Wander has been possessed, Lord Emon orders his warriors to kill the fallen warrior.
Wander tries to make his way to Mono's body only to be attacked by Emon's men, leaving him crippled and bleeding black blood. He is consumed by the oozing darkness and dies in the same manner as the Colossi. Dormin takes control of his body, transforming Wander into a huge shadowy beast. The dark entity explains that each Colossus contained a piece of his essence that had been sealed away. As Wander defeated each Colossus, the fragments embedded themselves in Wander's body. Once all the pieces of Dormin were reunited, he was able to fully possess the young warrior and manifest his corporeal form.
Lord Emon and his men quickly flee from the reborn Dormin, who attacks Emon's group with his enormous new body. The shaman casts Wander's ancient sword into a small pool at the back of the shrine, creating a whirlwind of light which engulfs Dormin, and by extension, Wander. Emon and his warriors race back across the collapsing bridge, returning to the Forbidden Land's entrance just before the bridge falls completely. The shaman looks back towards the Shrine one last time and states that, if Wander survived, he hopes the young warrior could one day atone for his crimes.
Mono at last awakens inside Shrine, resurrected by Dormin just as he had promised. Agro is also revealed to have survived her fall into the gorge and limps towards Mono with an injured hind leg. She follows Agro towards the pool into which Wander's sword was cast and discovers an infant child with two small horns on its head at the bottom of the empty basin; presumably the reborn Wander. Mono gently takes the child and ascends with Agro to the roof of the Shrine of Worship, discovering the Shrine's rooftop garden as the game ends.
- Wander is voiced by Kenji Nojima.
- Wander is sometimes mistakenly referred to as "Wanda," an error caused by the Japanese pronunciation of the name.
- Like the character Ico from the game of the same name (and also developed by Team Ico), Wander was originally meant to have horns at the beginning of the game but this idea was abandoned.
- Wander's garb has the magic sigil on it, found on Lord Emon's robes and the weak points of the colossi.