The Hangover star, 42, and his new fiancee Quinn Lundberg are planning an August (12) wedding, according to Celebuzz.com.
Invites sent to family and friends feature a drawing of Galifianakis and his 29-year-old bride-to-be, sketched by the actor himself.
A source says, "He made sure he looked like a little troll, while Quinn is a stunning tall blonde princess."
Last year (11) in an interview with Rolling Stone magazine, the movie star confessed he dreamed of starting a family with Lundberg.
He told the publication, "I've been wanting kids for 10 years. I'd love to adopt, have them naturally - all of it. I want, like, 15."