Sneaked or Snuck?

Sneaked or snuck? Which one is it?
Brian Klems addresses the answer:

'"Sneaked" versus "snuck" is one of those classic grammarian conundrums that you'll hear word enthusiasts debate all the time. Many people (like my sister) will say "snuck" without even slight hesitation, while supporters of "sneaked" (like me) will adamantly throw red flags on them, calling them out for improper use of our fine English language. But do we who say "sneaked" really have a case against the "snuck-ers" of the world?'

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