This angel shark's appearance changes in a shocking way when it yawns. When the shark yawns, its outer skin stays in one place while its gaping mouth and body seem to slide forward, like a turtle coming out of its shell.
The shark goes from looking mildly scary to terrifying. The effect of the yawn makes it look like a strange creature who is merely wearing a shark costume on its back.
From YouTube: "A Young Angel Shark in Tenerife on a night dive with Tenerife Diving Academy in the Canary Islands, who has a quick stretch and yawn, exposing its jaws and teeth. The Angel Shark is a protected species with the status 'critically endangered'"
See also: "X-ray of the Smithsonian's two-headed shark and other specimens"
