"I will kill you all"

Few minutes ago, my friends and I were playing against a group of people, and there were a riven that did an amazing damage. Now, since she was fed, I didn't mind it. It's Riven, that's her thing. At the end of the game, I checked the death recap to see the damage, and there were 2 skills that displayed normally, but the third skill icon that did a significant damage had no skill icon or description. I scrolled over to that icon to find out that it said the following:

"I will kill you all."

Shortly after that, we lost and I was unable to take a screenshot of the death recap.

My question is: Does this thing occur normally?