Caterpillar Song is a BMS (Be-Music Source) track by Bitplane featuring vocalist Yura Hatsuki (葉月ゆら), originally entered in THE BMS OF FIGHTERS 2010, The Evolution of War, where it placed 8th in the individual score division. Classified under the BMS genre of trip hop, the song moves at a deliberate 90 BPM and draws its lyrical and thematic inspiration from Lewis Carroll's *Alice's Adventures in Wonderland*. The lyrics, entirely in Japanese, inhabit the perspective of the story's hookah-smoking Caterpillar, referred to throughout as いもむし先生 ('Mr. Caterpillar'), portraying him as a hypnotic, confounding figure whose words muddle and beguile those who encounter him. An extended version of the track appears on Bitplane's album *Alice's Adventures in Wonderland*, and the in-game jacket art is derived from that album's cover artwork with the title text cropped out. The song's visuals were produced by a trio of creators: 原子の力, しきみ, and mashana. Caterpillar Song was added to maimai DX UNiVERSE PLUS in April 2022, with a staggered rollout across regions, arriving in Asian cabinets later that August and in Chinese cabinets in August 2023. The Master chart, designed under the Alice-inspired alias チェシャ猫とハートのジャック (Cheshire Cat and Jack of Hearts), weaves dense Slide and Touch patterns around the unhurried trip hop rhythm, while the Expert chart by はっぴー focuses on sustained Hold note sequences.