Ron’s actor, Rupert Grint, was spitting out fake slugs — not real ones. He’s said the scene used a giant slug prop in his mouth, and it was loaded with slime so he could cough it out on cue.

What it was

  • A prop slug made for the film scene.
  • It was reportedly slimy and unpleasant to film, which is why the scene stuck in people’s memory.

Why it looked real

  • The effect was built to look like Ron was vomiting slugs after the spell backfired.
  • Rupert Grint described it as one of the hardest scenes because he had to spit out the slug prop repeatedly.

In plain English

So the “slugs” were movie props, likely plastic or fake edible slugs with slime, made to look gross on camera.

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