Muppet took no mercies unfortunately (6,7)

I believe the answer is:

cookie monster

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'muppet' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.

'took no mercies unfortunately' is the wordplay.
'unfortunately' is an anagram indicator (a bad or unfortunate spelling).
'took'+'no'+'mercies'='tooknomercies'
'tooknomercies' with letters rearranged gives 'COOKIE MONSTER'.

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I've seen this clue in The Independent.

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