Ariados was one of the Masked Man's Pokémon, sent to stop Gold at Ilex Forest. Ariados bound Gold's Sunkern and prevented it from attacking. Since Gold disappeared, the Masked Man had Ariados spit web out to prevent his escape. Gold managed to throw his jacket away, to distract Ariados, who spit web out to bind the jacket. However, Ariados managed to spit web out from its back and tied Gold up, allowing the Masked Man to flee.
At the Lake of Rage, Gold teamed up with Silver to stop the Masked Man, whose Ariados went to attack the two. Their Quilava and Sneasel managed to intercept their attacks. As Silver went after the Masked Man, Gold was forced to fight Ariados and Houndour. Since Ariados and Houndour went to attack Aibo, the latter used Double Team, which caused Ariados and Houndour to hit and knock each other out.
None of Ariados' moves are known.