capricious

changeable

Governed or characterized by caprice; apt to change suddenly; freakish; whimsical; changeable.

Latin 'capricornus' (like a goat's unpredictable leap)

“I had to decide whether we took a hero or an author, which I soon learnt to do with capricious resolution.”

— George Meredith, Complete Project Gutenberg Works of George Meredith

“The Grutas de Rancho Nuevo Ecotourism Center is centered on a set of caves in which appear capricious forms of stalagmite and stalactites.”