Charlie Sheen became a grandfather Wednesday afternoon, according to a report from TMZ.

The Anger Management star's 28-year-old daughter Cassandra Estevez gave birth on July 17 to a baby girl named Luna.

It is the first child for Estevez and her high school sweetheart-turned-husband, Casey Huffman.

"It's impossibly a most wondrous day," Sheen told TMZ Wednesday, "My bucket list is a thimble!" The celebrity gossip site suggested that he was referring to being a grandfather as a huge portion of his bucket list that the rest is "thimble-sized."

Sheen first revealed that his eldest daughter was pregnant in January on the Late Show with David Letterman.

"Me as a grandfather, Dave . . . I don't know," Sheen joked to host David Letterman. "It's like the world's going to crack in half." Switching to a more serious tone, he added, "It's fabulous. It's just not a title I'm ready to adopt."

When Letterman asked Sheen if he would a good grandfather, he quickly joked, "Well, yeah, because you can leave the kid."

Watch the clip of Sheen discussing the news on Letterman here:

The news of Sheen's first granddaughter comes a day after ex-wife Denise Richards demanded full custody of his sons Bob and Max, who he had with Brooke Mueller, another ex-wife.

"[Richards] is prepared to tell the judge she would love to keep the boys permanently," a source told DailyMail Tuesday. Bob and Max were removed from Mueller's care in May due to the 35-year-old providing an "unsafe environment" for them.

"Denise has been essentially raising the boys since last summer, and she loves the boys as if they were her own," a source told RadarOnline Tuesday. The source also said that Sheen was supportive of Richards raising Bob and Max. Sheen said that the 42-year-old Richards was "the best possible mother they could have."