The actress drowned in California's Lake Piru a week ago in a tragic accident, with news of her death confirmed on Monday after her body was located.
Posting a picture of Rivera on Instagram, Criss said: "She was bold. She was outrageous. She was a LOT of fun. Naya made me laugh like no one else on that set. I always said it while we were working together and I've maintained it ever since. Her playful, wicked sense of humor never ceased to bring a smile to my face.
"She played by her own rules and was in a class of her own. She had a brashness about her that I couldn't help but be enchanted by. I also always loved her voice, and savored every chance I got to hear her sing. I think she had more talent than we would have ever been able to see.
"I was constantly moved by the degree to which she took care of her family, and how she looked out for her friends. She showed up for me on numerous occasions where she didn't have to, and I was always so grateful for her friendship then, as I certainly am now.
"And even as I sit here, struggling to comprehend, gutted beyond description - the very thought of her cracks me up and still brings a smile to my face. That was Naya's gift. And it's a gift that will never go away.
"Rest in peace you wild, hilarious, beautiful angel."
Investigators have confirmed that Rivera's death was an accidental drowning, with no signs of foul play or suicide, nor any indications that she was under the influence of drugs or alcohol at the time. body check tags ::