An example could be the lawnmower that works sometimes, but seems to have a mind of its own.
It could also be the literal word for having a mind of its own, to describe any being.
Learn English – What’s the word for something that has a mind of its own
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Best Answer
Usually, when something - mechanical/electronic/non-human animal- is described as 'having a mind of its own', it's because it doesn't agree with the person describing it. In those cases, the thing is often called by the personality perceived. Ex:
"An ornery old truck."
"A moody computer."
"A snobbish goldfish."
When something (like, my car) exhibits a multi-faceted personality, I am forced to concede that she has a soul.