Ash spent a lot of time in the Safari Zone in "The Legend of Dratini", attempting to catch as many Pokémon as he possibly could. However, all he managed to catch were 30 Tauros, as they always ran in front of his Poké Balls when he tried to catch another Pokémon. All 30 were sent to Professor Oak's lab.
Since Ash captured the Tauros in a banned episode, it led to some confusion from international viewers as they wondered how and when Ash had obtained these Tauros. The anime only mentions the events of the banned episode once, where Oak mentions that Ash captured the thirty Tauros in the Safari Zone, without giving the details on how he captured them.
The herd are mainly seen to be stampeding. Mostly, this occurs in the wide open space at the lab. Their stampeding has been put into good effect, as they woke up Ash's Snorlax when the Professor needed it. However, their stampeding has also damaged properties, like when Ash first returned to Pallet Town when they stampeded through a fence and when they stampeded through the lab, leaving a huge hole in the wall.
Ash decided to use one of the Tauros in his battle against Drake after sending his Snorlax to the lab. Initially, he was confused by Gengar's Confuse Ray and had to be recalled. Tauros was then sent out to battle Drake's Venusaur, which he defeated by himself. He then went on to weaken Dragonite before being defeated.
Ash sent his Heracross to Professor Oak's lab so he could use Tauros as part of a Tauros-battle tournament, which he went on to win. Tauros was also used against Gary, where he was defeated by Gary's Nidoqueen.
Upon Ash's return to Pallet Town following his adventures in Hoenn, the Tauros charged towards him along with his other Pokémon. However, in their excitement, they carried Ash off and he had to be rescued by Bayleef. During Ash's journey in the Kanto Battle Frontier, Ash used Tauros to battle against Salon Maiden Anabel.
The Tauros later reappear in SM042: Alola, Kanto!, where they are excited to see Ash again. In their excitement, they charge at Ash and cause him to blast off.
Despite capturing all his Tauros in green Safari Balls, and these being seen in storage at Oak's lab, Ash always uses regular red Poké Balls when sending his Tauros into battle. It is possible he released and recaptured the one he always uses so that he knows for sure it is his best one.
Katsuyuki Konishi (Japanese and English)
- The episode in which the Tauros were caught in was skipped in the dub due to featuring excessive gun usage and therefore not complying with the requirements of American children's television, and therefore being skipped in the vast majority of dubs that are based on the English one. This causes a plot hole as later episodes which were featured in the dub included his 30 Tauros without anything revealed in the dub on how he has them.
- Brock caught a Tauros at the same time that Ash caught his first Tauros. Because of this, some believe that Brock should own a Tauros, and the writers forgot about it in subsequent episodes. However, he caught him using one of Ash's Safari Balls, and therefore he is one of the thirty belonging to Ash.
- It has never been revealed whether Ash uses the same Tauros whenever one of them is transferred to him or if Professor Oak simply sends him a random one each time. However, it is likely that the one Ash uses is the leader of the herd.
- Despite them all being captured in green Safari Balls, they all have regular Poké Balls when Ash calls them into battle.
- Ash was offered a Rhyhorn in exchange for his Tauros after winning the Tauros battling competition. Ash had tried to capture a Rhyhorn in the Safari Zone, but a Tauros ran past and was captured instead. Despite this, Ash chooses to keep his Tauros.
- Tauros is Ash's only Pokémon to have used a one-hit knockout move.
- Tauros is the only Pokémon that Ash has more than one of.
At Oak's Lab
At Kukui's house
At Cerise Laboratory
At Pewter Gym/Home
Caught for someone else