Caprice

Ultimately, this word, which comes to us most recently through French, is associated with the Latin ericius meaning 'hedgehog' (AHD). 

To have--in the borrowed language of the AHD--"an impulsive change of mind...an inclination to change one's mind impulsively," or to exhibit "sudden, unpredictable action, change, or series of actions or changes" is to be a "curly" (riccio) "head" (capo): Caprice n. (AHD). However, the word was used with a slightly different compound form of caporiccio: fright, sudden start (AHD).

In music, the word maintains its Italian form (capriccio) to instruct the performer to play flowingly, with freedom. 

And finally, in French, the -cio ending was replaced with a simple -e.