This is a proof-of-concept teaser trailer/pitch for an animated feature film called Kariba. It was made by Blue Forest Collective, a South African animation group.
And it looks fucking awesome.
From Cartoon Brew, which has more info:
Kariba was conceived as a modern African fairy tale, combining the historical events surrounding the building of the Zambezi river dam wall and the local legend of the river spirit that caused its destruction. “We are using the rich history and mythology around this event,” Snaddon said. “Our aim is to make something that stands out as being uniquely African, a film that respects both its source material, and its audience, while being hugely fun and entertaining.”
And here’s some concept art:(https://vimeo.com/122076401)