When Brock joined up with Ash in Sinnoh, Bonsly was the only Pokémon he brought with him. Bonsly had shown signs of maturation, eventually learning the move Mimic in A Staravia Is Born!. In the next episode, after being captured by Team Rocket, Bonsly evolved into Sudowoodo to help free Brock and a Nuzleaf, defeating James's Carnivine in a battle. He was also shown to have gained a significant increase in his power and battling skills. Instead of being needy and heavily reliant on Brock's care, Sudowoodo was eager to help Brock in almost any task. He also has an odd tendency to salute Brock whenever he is called from his Poké Ball.
In Battling a Cute Drama!, Brock met a Trainer named Marilyn and quickly became irritated by Marilyn's superficial attitude towards Pokémon. He decided to teach her about the inner strength and beauty of Pokémon with a battle and used Sudowoodo as his first Pokémon. Sudowoodo scores a direct hit with Double-Edge, making Cherubi fall down dramatically. Marilyn ignores the fact it hit and remarks on how Cherubi took the hit, causing Brock to scold her some more. Brock orders Sudowoodo to use Mimic, causing it to fall dramatically too, followed by Fake Tears and Sudowoodo is soon sobbing on the floor. This causes Marilyn to start realizing the true battle strength of Pokémon. Wanting to move things along so he can view Marilyn's other Pokémon, James declares the round a tie.
Sudowoodo reappeared in Heart of Fire! Heart of Stone!, where it accompanied Brock to Alola. Sudowoodo was used to battle Olivia and her Lycanroc, only for the match to be interrupted by Team Rocket, who attempted to steal all of the Pokémon. When Team Rocket's efforts failed and they attempted to escape, Brock had Sudowoodo attack their mecha.
Being much younger than the other Pokémon in the group, Bonsly was portrayed as needy, childlike, and easily upset. Brock was often seen bottle-feeding him until he could eat solid food. Since his evolution, he has matured and is no longer a crybaby. In fact, he is very upbeat, as seen in All Dressed Up With Somewhere to Go!, when he recovered from a crushing disappointment almost instantly.
Bonsly occasionally took over from Max in getting Brock away from girls. However, rather than pull his ear, Bonsly would hit him with a powerful Double-Edge. He apparently did not want to share Brock, his "parent", with anyone else.
Since Brock brought another baby Pokémon onto his team by hatching Happiny from the Egg he won in the Pokémon Dress-Up Contest, Sudowoodo seems to have bonded with her, and the two frequently are featured doing activities together, almost as if Sudowoodo is an older sibling.
As a Bonsly, he was the only Pokémon owned by a main character that didn't eat Pokémon food, since Brock always fed him with a bottle. However, he did begin eating Pokémon food before he evolved in Leave It To Brocko!.
Sudowoodo is the only Pokémon to date that Brock caught onscreen through the standard method by battling him first.
Despite the fact that Brock specialized in Rock-type Pokémon as a Gym Leader, Bonsly was the first new Rock-type Pokémon in his team since his debut, which was 425 episodes before Bonsly was caught.
Sudowoodo was the first Pokémon in the anime to evolve by the method of knowing a certain move.