Whimsical (adjective)

1. Given to or characterized by sudden and unaccountable changes of mood or behavior.
2. Playfully fanciful or fancifully playful.

Origin:

From the word "whim" meaning "a sudden or capricious idea".

Examples:

1. The garden was full of whimsical sculptures.
2. The designer's whimsical approach to fashion was refreshing.
3. He had a whimsical sense of humor.
4. The decor of the room was whimsical and quirky.
5. She had a whimsical way of thinking that made her ideas unique.