I think you have an **Indian Lily Moth** (of the genus Polytela). It is considered a minor pest. Their habitat seems to only be around India and its surrounding area.
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Their worm matches yours ... smooth, dark, but red patches and white spots:
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If you dig in your garden, you may encounter these pupae:
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And they eventually grow into these beautifully-multicoloured moths:
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Here is a video showing their movements and their life cycle:
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