Sérgio Costa Stern Junior is a Brazilian voice actor known for his extensive work dubbing anime, animated series, and films into Brazilian Portuguese. Born on December 2, 1961, in Pintópolis, Minas Gerais, his path to voice acting was indirect; he initially studied psychology and later biology, graduating in 1983 and working in pest control for three years. Alongside this, he performed magic shows before formally pursuing acting, obtaining a provisional actor's registration in 1991 and enrolling in dubbing and theater courses, eventually securing a permanent professional registration.

Stern's voice is featured prominently in a wide array of anime series and films. He is a recurring voice for the character Meowth in the Pokémon franchise, providing the voice for the role in the television series Pokémon Sun & Moon and Pokémon XY & Z, as well as in several films including Pokémon the Movie: Volcanion and the Mechanical Marvel, Mewtwo Strikes Back Evolution, and Pokémon the Movie: I Choose You!. In the anime Radiant, he voices the character Yaga, and in Jujutsu Kaisen, he is the voice of Kiyotaka Ijichi, a role he reprised for the film Jujutsu Kaisen 0. His other notable anime credits include Adelheid von Schugel in Saga of Tanya the Evil, Halley Astray in Akashic Records of Bastard Magical Instructor, Jack the Ripper in Black Clover and its film Black Clover: Sword of the Wizard King, and Donquixote Mjosgard in One Piece.

Beyond these, Stern's voice work spans numerous other productions. He voiced Hamsterviel in the Stitch! television series, a Sangheili officer in Halo Legends, Cyborg 007 in Cyborg 009 The Cyborg Soldier, and Mirage in Transformers: Robots in Disguise. His filmography also includes roles in anime such as Kengan Ashura, BNA: Brand New Animal, Konosuba, Re:ZERO, and Samurai Champloo. In addition to Japanese anime, his work extends to Western animation and live-action films, including voicing Mike Wazowski in several Monsters, Inc. related projects, Jacques in Finding Nemo and Finding Dory, and Wheelie in the live-action Transformers films.