He's currently rolling out his 16th (!) book, A Tale of Witchcraft, and he stopped by Wednesday, Sept. 30's Daily Pop to tell E! co-host Carissa Culiner all about it.
According to Colfer, A Tale of Witchcraft is "a mystical story about witches and magic and this evil clan of men called the Righteous Brotherhood who try to exterminate magic."
However, there's much more to the book than meets the eye.
"Everything is an allegory for hate and fear and mental health," Colfer added. "So if I do my job well, I hope it helps parents have conversations with their kids about mental health and about depression; conversations that I'm sure a lot of parents are having right now."
Colfer reflected on this friendship, revealing one of his favorite things the actress used to do when he was in need of cheering up.
"A lot of people probably don't know this," he explained. "But Naya had the most incredible impressions and she was always, always ready to give you one if you were in a bad mood."
His favorite impression of Rivera's?
Well, it's very specific: "She had this one of Kim Kardashian on jury duty."
Colfer said it would "always make me belly laugh whenever I needed one."
Watch the complete interview with Chris Colfer on Daily Pop in the above clip!