Megan Fox decided to cover up her taut waist scrawled with tattoos during a Teenage Mutant Ninja Turtles appearance in Sydney on Monday.

But the 28-year-old American actress still flaunted some flesh, donning a sleeveless black top teamed with a fitted pencil skirt featuring a thigh-high slit down the centre.

The black-haired beauty wore silver ankle-strap heels to pose in a graffitied Sydney alleyway - that looked like it could have been right out of the TMNT set - with her co-star Will Arnett.

The actress flashed some flesh in a bold orange cut-out dress at the event, held at Sydney's Fox Studios.