Where the shape comes from
The head and striped brow of a tiger, cropped from the fuller picture of the whole animal drawn in 虎. It tops that very character, tiger, and appears atop a small family of others, among them 虑, to consider, to worry, where it mostly lends its shape and sound rather than any trace of the animal’s fierceness.
汉字 filed under 虍
No published character on HSK Guide is filed under this radical yet. 汉字库.