A Nestlé Lean Cuisine "meal in a bowl" held an unwelcome surprise for a Blackbutt woman when she discovered a large lizard's head among the pre-packed vegetarian ravioli.

The mother of four, who wished to remain anonymous due to fears that she would become known as the "lizard lady", said she'd chosen the frozen dinner in a bid to regain her figure after recently giving birth.

Describing the moment when she discovered the surprise, she told the Illawarra Mercury: "We weren't sure at first whether it was a lizard or a frog, but on closer inspection, we decided it was definitely a lizard.

"This wasn't your normal, garden variety lizard. I'm worried about where the rest of it is."

A Nestlé spokesperson told the Illawarra Mercury that the company has "zero knowledge" of the incident, but that the meal was probably prepared at its plant in Packenham, Victoria.