タイトルホルダー is the transliteration of Titleholder, a Japanese Thoroughbred racehorse born in 2018.

On the race 春の天皇賞 (Haru no Tennō Shō, aka Spring Emperor’s Prize) held on May 1, タイトルホルダー won the 1st place, which lit up the discussion on Japanese Twitter. Horse racing is quite popular in Japanese society (partly due to the gamble/lottery related), and inspired subculture projects such as the phenomenal ウマ娘 プリティーダービー (Uma Musume Pretty Derby). The naming of these racehorses is also an interesting topic.

Learn more on wikipeida about Titleholder or Uma Musume Pretty Derby.