A Sombra Cueio like your father... give up...
~ The Shadow

The Shadow is a villain who appears in the final two chapters of the first season of the Cueio Youtube series. The Shadow appears as a dark doppelganger of Cueio sporting an evil grin.

After Cueio is defeated by Lobi and leaves his friends Primo and Vaco behind, the Shadow appears and attacks him. Cuieo fights back and apparently vanquishes him, but he appears again, now grown into gigantic size and impales Cueio, proceeding to possess his body. Cueio finds himself into a dark, empty space, where a visage of Primo talks to him, reminding him that his fears brought the shadows. Cueio shrugs it off and tells he doesn't care, asking Primo to leave him alone. Primo shows him a vision of the outside, where he is possessed by the Shadow, who starts beating up Vaco. Horrified, Cueio attacks the light on the place, which breaks up as he regains control of his body and the Shadow vanishes.