gremlins

/G R EH1 M L AH0 N Z/
noun
  1. 1

    A mythical creature reputed to be mischievously inclined to damage or dismantle machinery.

  2. 2

    (by extension) Any mysterious, unknown source of trouble or mischief.

    โ€œWe rechecked everything, and we suspect gremlins in the database.โ€

  3. 3

    A young inexperienced surfer.

Source: https://en.wiktionary.org/wiki/gremlin, https://en.wiktionary.org/wiki/gremlins