two stills out of a video? How is it actually appearing? My guess based on those two images would be the model is just being moved though a plane. So what does the video (assuming that's what it is) actually do?
hard to tell in the second one since the elephant is obscured by the dancers a bit and disappears out of the top of the frame as well (and you can't go frame-by-frame in youtube) but that looks like a boole subtract, in the scene, or then composited onto other video in post.
The first definitely looks like the lion just moves forward through the plane with AO on the plane for the purple 'shadow'. And the purple surround that grows from the bottom either as a separate element or a tex on the plane or composited in post.
Neither looks more complicated, like you might get with the geometry, disconnected in a Fracture and a linear falloff to reveal. That would be more chunky as individual polys popped into view...