Whimsical

/ˈwɪmzɪkəl/ adjective easy

Playfully unusual or fanciful in a lighthearted, unpredictable way.

The children's book was full of whimsical creatures that defied any logical explanation.

Memory Trick

Whimsical comes from 'whim,' a sudden playful notion -- a whimsical design looks like it was built entirely on a string of fun whims.