Excadrill, as a Drilbur, first met Iris as a child after tormenting some Patrat and stealing their food. She challenged him and after being defeated countless times, Iris finally managed to get the better of the Drilbur and got him tangled in some vines. Unfortunately, he was dangling over a cliff. Iris saved him from a fall and the two began training together. Drilbur won all of his matches through one-hit KOs, never taking a hit in the process. They eventually entered a tournament, where he evolved into Excadrill while battling a Trainer's Druddigon and won, earning Iris a streak of 99 straight wins. Iris, looking to get her 100th win against a Dragon Master, challenged Drayden to a battle which he happily accepted. Excadrill put up a good fight against Drayden's powerful Haxorus, but he found himself taking hits for the first time. Haxorus soon knocked Excadrill out, and Excadrill, concluding that Iris liked winning battles more than she cared about him, closed himself off from her.
He was left at the Village of Dragons when Iris went to the Opelucid Academy. When Iris returned later she decided to take him along on her Journey to become a Dragon Master.
He was later introduced to Ash and Cilan in The Bloom Is on Axew! when Iris's Axew got stuck in the horns of a wild Scolipede, and both Cilan's Pansage and Ash's Snivy tried and failed to stop it. Reluctantly, Iris sent out Excadrill to help. But as soon as he came out, he stayed in his inactive state and refused to do anything. After Iris rescued Axew herself, Excadrill came out of his inactive state and attacked Scolipede after Scolipede inadvertently kicked him. He easily defeated it and sent it flying off into the horizon. Excadrill cried out in victory before going back into his inactive state.
Iris sent out Excadrill to help out in Dancing With the Ducklett Trio! when Ash and Pikachu went missing after falling down a hole. However, Excadrill refused to help, remaining inactive and forcing Iris to recall him. He appeared again for a short time in Emolga the Irresistible! to fend off a swarm of Swoobat, but as usual he just remained idle. He then fell for Emolga's Attract and was returned to his Poké Ball. Then in the next episode he was brought out by Emolga's Volt Switch, but still did nothing.
In Iris and Excadrill Against the Dragon Buster!, after Axew was knocked out by Georgia's Beartic, Excadrill was sent out to battle. After intentionally being knocked into a tree, Excadrill came out of his stasis and battled the Freezing Pokémon. He was knocked out and returned to his idle state of being curled up. Conversations between Ash, Iris and Cilan subsequently followed. Later that night, Excadrill was emotionally moved by Iris's heartfelt apology to him; she finally realising why he had lost faith in her and understanding his situation. Forgiving her, he wandered off while she slept and managed to learn how to use Focus Blast, but could not perform it properly. Iris then trained with him, and together they managed to perfect the move. With his confidence in his Trainer restored, Excadrill re-challenged Beartic, which resulted in a draw. Despite tying, Excadrill was still pleased with the results, embracing his Trainer in a hug.
Iris used Excadrill in the final round of the Club Battle in Club Battle Finale: A Hero's Outcome! in her battle against Ash and his Pikachu. After his Drill Run clashed with Pikachu's Quick Attack, Excadrill grabbed his opponent by the tail and flung Pikachu across the battle field before attacking with Metal Claw. Excadrill then attempted another Metal Claw to meet Pikachu's Iron Tail, however, he was hit by his opponent's attack. His Focus Blast met with Pikachu's Electro Ball, where the moves were shown to be equal. Excadrill soon landed a hit with Dig, although the move left Pikachu spinning in mid-air; putting more force behind his Iron Tail which hit Excadrill hard. Excadrill was finally able to better Iron Tail with Drill Run, distract Pikachu with Dig and win the match with one final Focus Blast.
In Battle For The Underground!, he was let out of his Poké Ball by Snivy when she found it amongst those that Team Rocket had stolen from the Nimbasa Pokémon Center, to free Pikachu and Axew from their cages with Metal Claw. He later helped fight off Dr. Zager's helicopter, while the other Pokémon worked out an escape.
In Stopping the Rage of Legends! Part 1, Excadrill battled Tornadus and Thundurus in an attempt to halt their rampage. He landed a hit on the legendary Pokémon by combining his Drill Run with Snivy's Leaf Storm, but was eventually defeated by the powerful opponents.
Iris chose Excadrill to participate in the Clubsplosion tournament in The Clubsplosion Begins!, he was sent out to battle Burgundy's Dewott and began battling it in the next episode. After withstanding an Ice Beam attack, Excadrill narrowly avoided Dewott's Water Pulse with Dig. However, after Dewott sent a Water Pulse into the hole, Excadrill took a lot of damage. He landed his first hit when he collided a short range Focus Blast with Dewott's Razor Shell and soon after, was able to knock its scalchops away. Iris then ordered a barrage of Metal Claw , but Dewott took the damage and countered with Revenge, heavily damaging Excadrill. After Dewott retrieved its scalchops, Excadrill met its Razor Shell with an equally powerful Drill Run, knocking Dewott back. The match ended with Excadrill overpowering Ice Beam with Focus Blast, hitting Dewott with a Dig and knocking it out with a final Drill Run. Later, in A Clubsplosion of Excitement!, Iris and Excadrill faced Montgomery and his Throh. Excadrill tried to use Drill Run, but Throh countered by grabbing Excadrill and using Circle Throw on him. Next Excadrill tried to use Dig, but Throh used Superpower on the ground, forcing Excadrill to resurface. The Judo Pokémon then defeated the Subterrene Pokémon with a Seismic Toss, eliminating Iris from the tournament.
In Drayden Versus Iris: Past, Present, and Future!, Excadrill battled Drayden's Haxorus once again. Excadrill started the battle with Metal Claw, which Haxorus was easily able to block, although it was pushed back by the hit. Excadrill then burrowed underground with Dig, and although Haxorus was able to dodge it and start a Rock Smash counterattack, Excadrill fired a Focus Blast at the Axe Jaw Pokémon before the move could hit, hitting it in the move-using jaw. After this Excadrill and Haxorus launched simultaneous Drill Run and Giga Impact attacks respectively, and were both knocked out by the resulting collision of the moves.
In Secrets From Out of the Fog! Excadrill was sent out to defend the Pokémon living at N's house from a Team Plasma Grunt's Muk, knocking it back with Metal Claw and eventually defeating it with Focus Blast.
Excadrill, just like Ash's Charizard and Dawn's Mamoswine before him, did not listen to his Trainer in his debut. However, unlike the other two, this was not in disloyalty to his Trainer. In reality, Excadrill is a very proud Pokémon who was once very caring towards his Trainer. However, after a devastating defeat, he became resentful to the point of blocking Iris out and distrustful of her advice in battle, considering her a bad Trainer who would make him lose again. He was later reassured after she apologised to him, learning a new attack and opened up to his Trainer once again.
Excadrill, as a Drilbur, was shown to be somewhat of a bully when he stole apples and abused a group of Patrat. Like Ash's Snivy, Excadrill has a passion for battling and won't ever give up, no matter what the circumstances. He always looks for different ways to improve. He is most often used in tournaments.