The line comes from The Rescuers Down Under, Disney's 1990 animated sequel set in the Australian outback. Villain Percival C. McLeach wants the golden eagle Marahute, while his goanna sidekick Joanna constantly hunts for eggs to eat, a gag borrowed from real goannas raiding nests. McLeach's warning protects the eggs he plans to use as bait rather than let Joanna spoil his trap. Decades later the isolated clip resurfaced on soundboards and in edits, where its specific wording became a reusable no, that is not yours reaction.
About this sound
A clip of Percival McLeach telling his egg-loving goanna Joanna that the eagle's eggs are not for her, from The Rescuers Down Under, used for denial jokes.
This short clip captures Percival C. McLeach scolding Joanna, his pet goanna, after she eyes the golden eagle Marahute's eggs as a snack. His flat, firm delivery turns a simple correction into a deadpan denial, stressing that these eggs are off limits and not hers to eat. Joanna's egg obsession is a running gag in the film, and that contrast between his serious tone and her sneaky appetite makes the line land as comedy. Lifted out of context, it sounds like someone caught in the act being told no in the most matter of fact way.