Totodile's debut appearance
Totodile first appeared in The Totodile Duel. Both Ash and Misty wanted to capture it, and although Totodile was stunned briefly by Pikachu, it managed to escape from their Poké Balls and knock them down with a powerful Water Gun. Totodile then came across Team Rocket, devoured their lunch itself, and sent them blasting off. Finally tracked down by Ash and Misty, Totodile jumped into the bushes just as they both threw their Lure Balls at it. They then found out that one of the Lure Balls had captured it. They decided to have a battle to decide who would keep it. Ash's Chikorita and Bulbasaur defeated Misty's Staryu and her newly evolved Poliwhirl, winning the battle and earning Ash the new Totodile.
Totodile was shown to be fairly romantic, as it quickly fell in love with an Azumarill in Love, Totodile Style. Totodile's advances were spurned repeatedly by Azumarill, and Brock's decision to teach Totodile to be successful in love was no more successful. But when Azumarill and Pikachu were captured by Team Rocket, Totodile ignored Ash and Brock's orders for it to come back and single-handedly chased Team Rocket down, locating them in a log cabin. Totodile was captured itself, but managed to cheer Azumarill up at least. When Azumarill's Trainer arrived with Ash and his friends, Totodile blasted Team Rocket down to help rescue Azumarill, but discovered that Azumarill was in love with Trixie's Golduck, who had defeated Arbok and Weezing. Brock consoled Totodile that although it can't win every time, love is worth fighting for. Totodile seemed to take this advice in its stride, falling for a Quagsire before the end of the episode.
Totodile was used fairly often during Ash's travels in Johto, but it wasn't used in many Gym battles, only once in A Goldenrod Opportunity against Whitney. However, Whitney's Miltank proved far too powerful, and her Rollout, already powered up in the battle with Cyndaquil, knocked out Totodile in one hit. In the rematch, Totodile performed better, launching itself into the air with Water Gun and landing on top of Miltank, but it was quickly shaken off and knocked out. Pikachu managed to win the battle. In Fight for the Light!, it was initially used against Janina, who Ash believed to be Jasmine, the Olivine City Gym Leader. Against her Onix, which had been coated in waterproof polish, Totodile was defeated by one Tackle.
Ash's Totodile battling in vain against Miltank
As one of Ash's only Water-type Pokémon, it was the first choice for Ash's team in the Whirl Cup, along with Kingler. In the battle with Christopher and his Kingdra, Totodile showed its skill by escaping a Twister and defeating Kingdra by using Bite on its snout while Kingdra used Hydro Pump, and the result of having too much water in its snout, it was sent off flying, and thus was defeated. In the head-to-head battle with Misty in The Perfect Match!, Totodile put up a good fight against her Poliwhirl by Headbutting it into a pillar, but was knocked out by a high speed dive and DoubleSlap.
Totodile was used briefly in a battle park in One Trick Phony!, where it defeated a powerful Charizard after using Scary Face for the first time. It also fought in the private Coastline Gym in Just Add Water, where it was revealed that he knew Slash. Totodile put up a very good fight in the underwater arena against Dorian's Lanturn, but Ash's inexperience in such battles and a type disadvantage caused him to lose.
In Pop Goes The Sneasel, Totodile was sent out to battle a wild Sneasel that was preventing the retrieval of the Sacred Fire needed to begin the Silver Conference. However, through a combination of Slash and Shadow Ball, Totodile and Ash were sent flying back. Harrison later defeated and captured Sneasel.
Totodile dancing in excitement after defeating Sneasel
It joined Squirtle and Phanpy in Ash's battle against Macy in Love, Pokémon Style. It squared off against her Slugma, who was quickly swapped with her surprise entrant, Electabuzz. Later in the battle, the two matched up again, and the type disadvantage was evident - Totodile's water was blocked by Light Screen, and an attempt to Headbutt through resulted in a ThunderPunch knockout.
Totodile redeemed itself in a battle against Harrison in Playing with Fire!, settling the score with Sneasel. Totodile bit down on Sneasel's arm to prevent a Metal Claw, and knocked it out with its tail. Its victory dance was very popular with the audience. Totodile's Scary Face attack had no effect against Harrison's Hypno and it was taken control of with a Hypnosis attack. A Psychic took it out of the match.
Ash left Totodile at Professor Oak's Laboratory, along with his other Johto Pokémon, when he departed for the Hoenn region.
Advanced Generation series
In a special episode, it was seen squirting Cassidy and Butch with a Water Gun attack but was fired back again. Totodile had its revenge later by squirting them with a Water Gun again and it hit. Later, it was seen blasting Cassidy and Butch off and destroying their helicopter. It also appeared in the Christmas special, where it was hanging out with Ash's, Brock's and Misty's Pokémon. Totodile managed to retrieve one present for Delibird. It was also seen creating the Snorlax Snowman.
Diamond & Pearl series
Totodile appeared in An Old Family Blend! alongside Ash's other Pokémon. It was found dancing in a water fountain and affectionately nibbled on Ash's head before being recalled to its Lure Ball. Later, it helped to put out the fire caused by Cyndaquil, together with Corphish and Piplup. Totodile was not seen participating in the Lily of the Valley Conference.
Best Wishes series
Totodile was reunited with Ash in The Dream Continues!, where it and the rest of Ash's Pokémon posed in a group photo with him.
Totodile is a highly energetic Pokémon. It is always happy and shows this by dancing, a theme that is focused on when it is released from its Lure Ball, even when being called into a battle. It also unabashedly introduced itself to Larvitar first in Entei at Your Own Risk, energetically swinging Larvitar around in a circle. However, when need be, Totodile can be a powerful opponent, as seen when it managed to defeat Harrison's Sneasel, who had been causing trouble for Ash and Harrison earlier on in Pop Goes the Sneasel.
Totodile also acts as a comic relief character, as its tendency to dance is shown in many important matches, frustrating Ash, and confusing its opponents. Its most significant battle, defeating Harrison's Sneasel, depicted it biting Sneasel's hand and dancing around whilst thrashing Sneasel into the ground. Its Scary Face attack has also been used as a joke a couple of times, one being in a battle with Duplica's Mini-Dit, where Totodile laughed at its imitation of the move before continuing the battle.