There is a glitch whenever Jak walks in front of a mirror that causes a slightly different model of Jak with dark grey horns to appear alongside the "reflected" second model of the room, initially suggesting that Jak was used as a test model for shaping Dark Jak's horns. However, a 2003 promotional contest advertisement hosted by Cartoon Network's programming block Toonami features a higher resolution model of Jak with white horns instead, suggesting that the model sent to Cartoon Network still had the horns on them and they just altered the model for the advertisement, or that Jak was originally supposed to have visible horns like Dark Jak.