The actress was appearing on The Tonight Show with Jay Leno when Jay Leno asked about a recent photograph of Hudgens in Hawaii sporting the ink on her foot.
Hudgens said: "It's fake. I have this mad obsession with drawing over myself. I cannot help it!
"I draw all over my hands, all over my arms, obviously my foot; it's fun. It's hard to commit to a tattoo. I have a few but when you write on yourself it's not such of a commitment. It's more like art."
Watch Vanessa Hudgens talking to Jay Leno below:
> Read Digital Spy's review of Journey 2: The Mysterious Island
During the interview to promote upcoming movie Journey 2: The Mysterious Island, the actress also spoke about her love for sky-diving, showing footage of a recent dive.
Talking about Journey 2, she added: "I did my own stunts. I love doing my stunts, I'm an adrenaline junkie, so any stunts I could do I would do. But I got whiplashed really bad so for a few days I couldn't turn my neck. It was kind of awkward."
Journey 2: The Mysterious Island sees Josh Hutcherson reprising his Journey to the Centre of the Earth role of adventurer Sean as he sets out to find a mysterious island with his stepfather (Dwayne Johnson) in order to rescue his missing grandfather (Michael Caine).
Watch Vanessa Hudgens talking to Digital Spy about Journey 2: The Mysterious Island below: