Mostly known for his covers of rock songs with Animaniacs voices.
Oreo (stylized o_re_o, formerly known as Oreo the Animaniacs Guy), born on March 30 2007 (age 19) in the Czech Republic has gained quite a bit of popularity with his covers.
Most people liking them, some not so much.

He got into Animaniacs in 2020 thanks to the announcement of the Animaniacs Reboot (as well as known as Animaniacs 2020).
His love for the show grew and grew over time, but not until falling out of love with the show in July 2023, the same year the show got cancelled.

Because of that, he moved on from Animaniacs to another show he started liking in May 2023. Helluva Boss, a Youtube adult cartoon series made by Vivienne Medrano aka Vivziepop and her self-funded company Spindlehorse.
This resulted to change his content from Animaniacs to Helluva Boss. Which reduced his views immensly, but he’s still going at it! But he also proved to like Hazbin Hotel quite a bit after the series on Amazon Prime came out.

This also applied to the covers as well. Oreo started covering songs from Hazbin Hotel and Helluva Boss. As of 2026, Oreo has went on a brief hiatus from music, planning to come back sometime in 2027.

Side projects:
The Loonatics – formed in 2023, broken up in 2025 due to personal drama with the co-founder
The Meatchewers – no planned activity (a supergroup consisting of him, Cliqueater, Coingamer and Sickbeet)