Where the shape comes from
A dog standing on its hind legs with the tail curled up — 大 with a dot added for the ear cocked forward. On the left of a character it is redrawn as 犭, three strokes suggesting a lean animal in profile, and it marks dogs first and then four-legged animals in general: 狗, 猫, 猪, 狼. Where a word for an animal has 犭 on the left, expect a beast rather than a bird or a fish.
汉字 filed under 犬
No published character on HSK Guide is filed under this radical yet. 汉字库.