The fruit is biggest at the top and decreases in size as it goes down. It has a flat bottom. Like all devil fruits, it has a stem and is covered in spiral patterns.
Strengths and Weaknesses
The biggest known strength of the fruit is giving the user the ability to fly. As a nue, the user seems to be capable of fighting and causing destruction, as shown when Toratsugu attacked Lark and Kikuhime's wedding ceremony. The nue form is large enough to carry people on its back. No weaknesses are known aside from the standard Devil Fruit weaknesses.
Toratsugu uses his fruit in combat, as shown when he fought against Lark and later Luffy, and also uses its ability to fly in order to travel to places quickly and make escapes. When he lived alone as an outlaw, he seemed to be in his nue form most if not all of the time.
The Tori Tori no Mi, Model: Nue grew on a beach somewhere in Wano Country. It was discovered by Toratsugu after he escaped from prison, and he ate it out of hunger.
The nue was originally stated to be a bird resembling the green pheasant. Now, it's more often described as having the body parts of various animals, to which it's sometimes called the Japanese chimera. The Genpei Jōsuiki describes it as having a chicken's torso. It's also often said to have an eerie bird cry, resembling that of the Scaly thrush, also called a nue.
However, the nue that Toratsugu transforms into doesn't appear have any avian characteristics aside from flight. This makes the Devil Fruit being a part of the "Tori Tori no Mi" series rather odd.
The kanji for nue, 鵺, uses the kanji for night, 夜, and bird, 鳥, which may contribute to its inclusion in the "Tori Tori no Mi" series.