Tep first appeared as one of the Pokémon owned by Professor Juniper along with the other Unova Starters, Snivy and Oshawott. While he sloppily ate some berries he roasted with his flames, Tep got into a fight with Snivy after getting juice on its tail. The two fought each other until they were broken up by Oshawott who had gotten angry and easily knocked them away. Later, they were delivered to an impatient Black so they can be the Pokémon of the new upcoming Trainers. After being sent out of his Poké Ball, Tep and Snivy get into a fight once more and is again stopped by an enraged Oshawott. Tep runs off and Black follows him, leaving Snivy to suffer the wrath of Oshawott. Eventually Black finds Tep stuck on a tree and rescues him from a wild Sewaddle and takes him as his own Pokémon. Later, Black goes to a library to look up the evolved form of Tepig so he can decide an appropriate nickname for Tep. Tep assumes that Black meant that he wasn't happy with his present form and runs away. Black follows him and after finding out the reason why Tep ran away, decides to give him the nickname "Tep" instead of a name based on his final form.
After some adventuring, Tep is introduced to the Tepig of White, Gigi and becomes friends with her. White, needing a male Tepig to go with her female Tepig in her media shootings, decides to employ Black and Tep after the former runs up a huge bill that he now needs to pay off. Tep and Gigi are then paired up in several shootings, such as movies or commercials.
Tep is later used against N in Accumula Town where he is almost defeated by the young man's powerful Pokémon. With words of encouragement from Black, Tep manages to get back up and defeats his Tympole, allowing N to decide that the battle is over and leave.
Tep, alongside Cheren's Snivy and Bianca's Oshawott, is used in the Striaton Gym against the Gym Leaders, Cilan, Chili, and Cress. Eventually, they manage to defeat Chili's Pansear, allowing them to win with three to one after the time limit runs out.
Later, in Castelia City, Tep is seen starting the evolution process into his next stage. This causes White to freak out at the thought of losing her two Tepig duo between Tep and Gigi; she grabs Tep and shakes him violently to get him to stop evolving. In his Gym Battle against Burgh, Black considers using Tep but decides against so when he remembers White's refusal against it.
