The Duchess was formerly one of Puss's many enemies but in Season 3, she became a member of the Senior Puss Squad. In Season 4, it is revealed she is the witch Maldonna.
She is a heavyset woman with brown hair kept tied in balls who wears goggles. She wears a brown dress with white sleeves and green stripe pattern. She is missing her right foot and replaced it with an iron foot. Her iron foot can shoot iron arrows at will. Edit
When we first meet the Duchess she is evil and incapable of doing magic herself. She has an obsession with power and gold. She cares for no one but herself and is willing to manipulate anyone to get her way, including a young child (Cleevil) and using Artephius's affection for her against him. She is fueled by her search for power and vengeance against Puss for cutting off her foot. Her cruelty climaxes when she manipulates a child into lying to Puss and the town for her own gain, alienating the child in the process.
By Season 3, she turns over a new leaf after joining in a truce with Puss to defeat the Bloodwolf. A more sympathetic side of the Duchess is shown during her time with the Senior Puss Squad. It is revealed that while she does love Artephius, he is too far gone (losing his sanity etc.) for them to be together. She later confesses to the Senior Puss Squad that she has had no friends other than them and can't even remember her own childhood, parents, and a large portion of her life. She grows to care for the others (Goodsword, El Guante Blanco, Golem etc.) as her best friends.
It is not until her time with the Eldrich Sisters that her true identity is revealed and her ability to use magic on her own returns. The Eldrich Sisters took her powers away.
The Duchess is at first incapable of performing magic by her own power. Instead she kidnaps and captures wizards in "soul bottles" and uses a special weapon to manipulate their magic as her own.
When she regained her powers, she became surprisingly powerful and formidable. She could blast bolts of lightning from her hands, fly without her bottles, use magic without wizard souls, use telekinesis to attack the Bloodwolf and bring suits of armour to life.
Before she was the Duchess, she was Maldonna, one of the Eldritch sisters, four powerful witches intrusted with guarding four fragments of the gem centerpiece of the Crown of Souls. When she was young, she decided to cash in on her "witchy" upbringing and wrote a tell-all book about herself and her sisters. Her sisters were so furious that they cursed all of history and the present to forget Maldonna. They wiped Maldonna's memories, stripped her of her powers and banished her, erasing her from history. The sisters forgot her and Maldonna's tower disappeared.
On her last meeting with Puss in Boots, during their battle, Puss cut off the foot of the Duchess in self defense when she tried to set him on fire.
Puss: Puss once met her at some unknown point and cut off her foot, which she is still angry about. He keeps apologizing for the foot but will still engage her when she commits evil. She hates him for the foot thing and wants to kill him. However, they make amends to stop the Bloodwolf and remain allies/friends afterwards as well, as The Duchess is a member of the Senior Puss Squad.
Artephius: The two used to be in a relationship, but it ended on bad terms. Since Artephius is still half crazed, it remains to be known how the relationship ended but Duchess implied he left her. Despite this, the two still have feelings for each other, with Artephius telling her he still loves her. While she is evil and wants to use him for his power, it is implied she still loves him (but still mostly wants his powers) as she was moved by the fact he remembered the time they made a heart shape necklace and split it in two, one for each of them and she still kept it (claiming because it was gold). She gets annoyed with him whenever she meets him and even threatens to beat him (mostly because he has lost most of his sanity and is senile).
- For some reason, whenever she shows people the foot Puss cut off she keeps showing the left foot first, which is still attached and fine before she says "Other foot,"and shows them her right iron foot.