It's large puppets on long sticks, controlled by puppeteers standing waist deep in the lake.
长棍上有一个大的木偶，由操纵木偶者在及腰的湖水中控制。
英语百科
George Lawrence Stone
（重定向自Stick Control）
George Lawrence Stone (1886–1967) was an influential American drummer and author.
He wrote the books Stick Control for the Snare Drummer (1935) and Accents and Rebounds for the Snare Drummer (1961). Among his students were Joe Morello, Gene Krupa, Lionel Hampton, and Vic Firth.