On Aug. 10, the couple will marry in an "underwater-themed" ceremony before 200 friends and family in Los Angeles, the tattoo artist tells PEOPLE.
Drawing from their mutual love for H.P. Lovecraft's short story "The Call of Cthulhu," about a character that is half-man, half-octopus, Von D assures PEOPLE that she and the electronic musician's ceremony will be "the furthest thing from traditional."
Previously engaged to Sandra Bullock's ex-husband Jesse James, who married drag racer Alexis DeJoria in March, Von D will have a big day that will include everything from various blue- and green-colored food to performers dressed as mermaids.
And her dress will fit the part too!
"It will have a sleek silhouette and include hints of iridescent teals, blues and deep violet ombré gradients," explains Von D, who has called upon Falguni and Shane Peacock to make the gown, which Deadmau5 is helping design. "I didn't know the dress was supposed to be a surprise," she adds.
However, superstitions are the last thing on Von D's mind. "Being with Joel is the only thing that feels more natural than tattooing," she says of her fiancé.
Adds Deadmau5, 32, "Our wedding is merely a celebration of that love and commitment we live in already."