Head on water, Wikie the killer whale stared at his handler in front of him in his pond, he listened to something from his handler, then suddenly said loudly, "Hello."
Speech is perfect imitation, but surprisingly fluent so well understood by humans.
This is the first scientific evidence of how the pope mimicked human language, including when he uttered the word "Amy", which is the name of the handler.
The whale can also say "Bye-Bye" and "One-Two-Three" or "one, two, three".
"We do not expect perfect imitations like parrots," said researcher Jose Abramson of the University of Complutense, Madrid, on research published in the journal Royal Society B.
When pronouncing six different words or phrases, Wikie tries to imitate them perfectly, though the whale's vocal anatomy is completely different from the human vocal anatomy.
It's hard to hide his joy at Wikie for the first time to say a word in human language, Abramson told AFP.
"When we teach the word 'hello' and he voiced it, emotional responses arise from the handlers, for us (the researchers) it is very difficult not to say anything," concluded Abramson.