Ink and Skin Studios in Kentucky, USA, do the creative designs in exchange for a donation to charity.
They shared pictures of their designs - which include baby Yoda, Deadpool and Anna and Elsa from Frozen - to Facebook and parents swiftly flocked to the comments to share their thoughts.
Some highlighted potential health risks Sharpies pose to children's skin.
Faye Leonhardt said: 'I love this, but I understand "Sharpies" are not good for skin.'
Matthew Rhoads said: 'Not opposed to this idea but I don't know how safe sharpie is on your skin.
'Obviously there's gonna be the "we used to draw on ourselves and we're fine" comments but you're fine now.
'You don't know long term effects. It's still a cool idea maybe just use something different if possible.'
Others claimed the fake tattoos would encourage children to get real ones.
Brandi Tabor said: 'Nope. Consider it the gateway drug to the real thing.'