Morgan, a captive killer whale owned by SeaWorld, was caught on video (below) in May beaching itself and laying motionless outside its tank at the Loro Parque aquatic park in Tenerife, Spain.
The Orca beached itself for at least 10 minutes while visitors left the area, notes RT.com.
In the video, most of the park guests seemed oblivious to what was happening, although a few reportedly stopped to take selfies with the beached animal.
When killer whales beach themselves it is often a suicide attempt. The giant creatures sometimes leave the water to hunt, but do not stay on an outside surface for long as their massive weight can damage their internal organs.
The same killer whale was reportedly seen banging its head against a metal gate in April.
This video was filmed by an anonymous activist who gave the footage to the Dolphin Project, an animal rights organization, notes the Daily Mail.
The Dolphin Project said: "We cannot explain the reason for her behavior. Sadly, Morgan was still out of the water by the time the videographers had to leave."
Loro Parque said in a statement: "The video published by the Dolphin Project on its website is a new attempt at manipulation through exaggeration and dramatization of a completely normal situation in which there is no problem for the animals."
In 2015, a video surfaced of Tilikum, a killer whale at SeaWorld San Diego, floating on top of his tank. Some killer whales at SeaWorld San Antonio were said to have dental trauma from chewing on their tanks.
"Every single orca that I observed had significant wearing on their teeth, specifically on the lower mandible," Heather Rally, a PETA veterinarian, told The Dodo in August 2015.
"They start chewing on their tanks," Rally added. "There's boredom there as a factor, and there's also stress … as soon as they start doing that they start to traumatize their teeth."