BioClay's Krokorok was the first Pokémon Clay used to battle against Ash during his gym battle. Clay's Krokorok was paired up against Ash's Oshawott as Pikachu initially wanted to battle it but Ash realized that an Electric type against a Ground type would be a bad idea. At the beginning of the battle, Clay's Krokorok had the upper hand as its Sandstorm managed to get sand in Ash's Oshawott's eyes and it also made it harder for Ash's Oshawott to accurately attack. Clay's Krokorok managed to hit Ash's Oshawott with a Bite and a Stone Edge attack but it wasn't enough to knock it out. Ash's Oshawott used Water Gun to clear up the Sandstorm and then it began its counterattack. Clay's Krokorok was repetitively hit with multiple attacks from Ash's Oshawott including a super effective Aqua Jet and Razor Shell combo that ended up being too much for it and it was knocked out.
|Move||Type||First Episode Used||Notes|
|Dig||BW 63||Dodged Mijumaru's Aqua Jet by digging underground|
|Sandstorm||BW 63||Satoshi's Mijumaru got sand in its eyes because of it but it used Water Gun to suppress the storm|
|Bite||BW 63||Got a hit in while sand was still in Mijumaru's eyes|
|Stone Edge||BW 63||Dent noted it was quite effective against Mijumaru|