Originally a recurring Pokémon, Krookodile first debuted as a Sandile before evolving into a Krokorok.
Despite losing to Ash's Pikachu, Krokorok later chose to join Ash's party and after evolving into Krookodile, it has since gone to become one of Ash's strongest Pokémon in Unova.
As a Sandile, he was mischievous that he caught Pikachu, Axew and Oshawott with his same kind. But he also has a caring side, in which he saved a group of wild Pokémon when he sensed danger. As a Krokorok, he continued to be compassionate and smart, but he became impulsive too, causing a lot of troubles that he didn't think about.
Also, he tends to react suddenly without warning. However, the most notable point is, when he loses his sunglasses, he becomes nervous and frightened and will do everything to find them, especially when he was a Sandile and a Krokorok.
As a wild Pokémon
Season 14: Black & White
Krookodile first appeared as a Sandile in A Sandile Gusher of Change! where it was given the nickname, the Sunglasses Sandile because of the sunglasses it wore. At the time, Sandile was also the leader of a group of fellow Sandile who all lived near a local spa resort with the Sandile group often causing trouble, all for the sake of getting attention from the owners. It was later revealed that the group was actually attempting to save the other Pokémon in the area because the Sandile themselves knew that in advance that a geyser would soon erupt. With the help of Ash, Iris, and the son of the spa resort owner, Dan, Sandile was able to save the Pokémon. In the end, Sandile was shown to have gained respect for Ash, and as such, began to follow him, presumably abandoning his fellow Sandile or leaving them to serve as guards for the spa.
Sandile returned in Here Comes the Trubbish Squad! where he sought to battle Pikachu. Sandile attacked by randomly using Stone Edge, endangering the lives of a group of young children who were nearby. Both Pikachu and a wild Trubbish intervened, sending Sandile blasting off with a combination of Sludge Bomb and Iron Tail.
Sandile reappeared in Dancing With the Ducklett Trio!, going so far as to separate Ash and Pikachu so that Sandile could personally battle Pikachu. However, a wild Ducklett stole Sandile's sunglasses, stopping the battle. Sandile was left deeply saddened by having his glasses stolen and lost his confidence, becoming cowardly. With Ash and Pikachu assisting him, however, Sandile was able to beat the Ducklett despite the type-disadvantage and reclaim his sunglasses. After being healed at the Pokémon Center, Sandile finally got what he'd spent a long time hoping for: a battle with Pikachu. Sandile dominated the battle right from the very beginning and even evolved into Krokorok. However, Pikachu gained the upper hand and sent Krokorok blasting off when Pikachu's own Electro Ball attack collided with Krokorok's Stone Edge, causing the stones to hit Krokorok and send him flying off again.
Season 15: BW Rival Destines
Ash and his friends found Krokorok with Krokorok helping them find Pikachu. A series of flashbacks then revealed that Krokorok had followed the group through various locations, including Nimbasa Town and Nimbasa City and it was also shown that Krokorok had been the one responsible for throwing a pen into a Klinklang during Evolution Exchange Excitement!.
After a long absence, Krokorok returned at the end of Explorers of the Hero's Ruin!, still harboring his dream of defeating Pikachu with his appearance startling Ash, Iris and Cilan.
In Battling the Bully!, Krokorok and Pikachu engaged in battle yet again with both Pokemon being sent flying off.
During a battle between three youngsters, Krokorok allowed Ash to use to help Mick learn the techniques associated with battling. Krokorok later teamed up with Pikachu under Mick's command in a Double Battle against a Seismitoad and Scolipede belonging to the father of a young boy, Sean. Krokorok and Pikachu eventually won while Krokorok later fought Pikachu with the intention of settling their rivalry once and for all. After a fiercely-fought battle, Pikachu eventually won despite the type disadvantage which left Krokorok greatly depressed by the loss. Krokorok then attempted to leave but Ash then offered Krokorok the chance to join his team with Krokorok happily accepting with Ash catching Krokorok in a Poké Ball seconds later.
Season 15: BW Rival Destines
In An Amazing Aerial Battle!, with Krokorok now a permanent member of Ash's team, Krokorok was used in Ash's Gym battle against Skyla.
Krookodile battled against Skyla and her Swoobat and was defeated with Air Cutter. He and Ash did some training with Brycen and his Beartic. It was used in the Icirrus City Gym where he was used against Brycen's Vanillish but was quickly recalled. He was later used against Brycen's Beartic where he won, winning Ash the Freeze Badge. Since it fully evolved it became a real powerhouse in his team defeated Iris' Dragonite with its new power and its speed has increased, along with Stephan's Liepard and Sawk.
|Bite||A Sandile Gusher of Change!|
|Dig +||A Sandile Gusher of Change!|
|Stone Edge +||Here Comes the Trubbish Squad!|
|Crunch||Battling the Bully!|
|Dragon Claw +||Ash, Iris and Trip: Then There Were Three!|
|Aerial Ace +||Strong Strategy Steals the Show!|
|+ indicates this Pokémon used this move recently.*|
- indicates this Pokémon normally can't use this move.
- He was set to appear in Team Rocket vs. Team Plasma (Part 1) but the episode, along with Team Rocket vs. Team Plasma (Part 2), was postponed and eventually cancelled.
- Krookodile is currently Ash's only -type Pokemon to have used/learned any Dark-type moves.
- Prior to capture, Krookodile inherited the blast off gag from Team Rocket.
- Krookodile, like other recurring Pokémon, has an item it carries around, its sunglasses, but was the first to have been caught by Ash.
- Krookodile is the third Pokémon that Ash caught who had an accessory, the first being Squirtle (they both have Sunglasses) and the second being Sceptile (who had a twig).
- When the sunglasses that Krookodile wears are knocked off, it seems to always have a nervous breakdown, suggesting it may be a comfort object.
- Krookodile, like Ash's Primeape, evolved before it was caught.
- Krookodile's sunglasses grew in size when he evolved.