Kagerou is said to have a calmer demeanor than one would expect from a werewolf. Like Keine Kamishirasawa and her were-hakutaku transformation, Kagerou acquires some characteristics of a wolf during a full moon, but she also has the ability to turn into an actual wolf (as demonstrated during her spell cards). To be exact, she is a were-Honshu wolf. Honshu wolf is a species of wolf that has gone extinct in the outside world.
Her first name Kagerou (影狼) literally means "Shadow Wolf". It is also homophonous to the word Kagerou (陽炎), which means the shimmering of hot air, which refers to Honshu wolf's state of extinction. Her surname, Imaizumi (今泉) is a reference to the Japanese zoologist Yoshinori Imaizumi (今泉吉典), who first researched Honshu wolf. It's spelled with the characters for "now" and "spring".
Kagerou has dark auburn hair and red eyes. She has two wolf ears. She wears a dress which is based on the design of the Hanafuda card for Pampas Grass and the Full Moon. The red on the dress represents the red sky, the white represents the moon, and the black trim with a hash pattern at the bottom represents the hill of pampas grass. At the neck of her dress is a red amulet. She has long, red nails. There also appears to be black fur poking out from under her sleeves. It is implied that she is human on any other night other than the full moon, but unknown what she looks like as a human.