Who Made Happy Horse?
The mystery behind the model that "air-dropped" onto the leaderboard.
The Mystery
In early April 2026, a model called “HappyHorse” quietly appeared on the Artificial Analysis AI Video Arena leaderboard. With no launch event, no press release, and no corporate backing, it surpassed Seedance 2.0 with an Elo of 1333 and triggered what the tech community called a “decryption race.”
Clues emerged quickly. The project website listed Mandarin and Cantonese before English in its language selector. The name “Happy Horse” fit perfectly with 2026 being the Year of the Horse in the Chinese zodiac — a cultural hint that pointed to a Chinese team.
The Connection to daVinci-MagiHuman
X user Vigo Zhao performed a point-by-point comparison of HappyHorse's public benchmark data with known models and found a near-perfect match with daVinci-MagiHuman, an open-source model released on GitHub on March 23, 2026. The visual quality (4.80), text alignment (4.18), physical consistency (4.52), and WER (14.60%) matched exactly. Even the website structures and architecture descriptions appeared templated from the same source.
The Teams Behind It
Sand.ai (砂岱科技)
Beijing, China
Founded by Cao Yue, Sand.ai focuses on autoregressive world models. They are believed to have optimized the daVinci-MagiHuman base model into HappyHorse, with targeted improvements for the evaluation scenario — particularly around portrait quality and audio-visual sync.
GAIR Lab
Shanghai Innovation Institute (SII)
The Generative Artificial Intelligence Research Laboratory, led by Professor Liu Pengfei, co-developed daVinci-MagiHuman. Their focus on large-scale multimodal pretraining provided the foundational research behind the model's unified Transformer architecture.
Why “Happy Horse”?
2026 is the Year of the Horse (马年) in the Chinese lunar calendar. The name follows a playful tradition in the Chinese AI community — earlier in the year, another model called “Pony Alpha” used a similar zodiac-themed naming approach. Given that the founders of both Tencent (Ma Huateng) and Alibaba (Ma Yun / Jack Ma) share the surname Ma (马, meaning “horse”), speculation about corporate connections was inevitable — though no direct affiliation has been confirmed.
The Strategy
According to analysis by 36kr, HappyHorse appears to be a deliberate strategy to validate the model's performance ceiling under real user preferences. By submitting to a blind-test leaderboard (where users compare outputs without knowing which model generated them), the team could verify that their optimizations translated into actual perceptual quality gains — not just benchmark number improvements.
This “stealth validation” approach also generated massive organic attention, effectively creating a marketing event through mystery rather than through traditional product launches.