Dee and Dum are twin gatekeepers of the Hatter territory. Their nickname to those not aligned with the Hatters is the Bloody Twins. They also have the ability to turn into adults.
Dee and Dum have very similar appearances, and if not for their different eye colors- Dee has blue eyes and Dum has red eyes- would be impossible to tell apart in child form if they were to dress alike and speak alike. As they are not identical twins, however, their eye color is one of the ways to tell them apart. In child form, they have short black hair and uniforms that are near mirror images of each other, except that Dee's is in blue and Dum's is red and the chain on the front of the uniforms is identical. In adult form, Dee wears his hair longer and tied back with a blue ribbon while Dum's hair is shorter, black and red barrettes holding back his bangs on one side.
The twins are childishly cruel, yet retain a sort of innocence in their cruelty. This innocence does not extend to their actions towards Alice, for when they grow especially attached to her, they do not behave as children. They like to skip work and kill for the fun of it, saying their are playing with whomever had the misfortune of being their victim. Both twins prefer axes to guns, "because axes are more fun." They look up to people who are mature or who benefit them, but everyone else (except Alice) will be subject to their insults and/or teasing. Because they are young, they are spontaneous and live more in the moment than most other people.
While not much is known about their pasts, at one point they were shunned by people for being too creepy. This leads them to expect Alice to abandon them at various times throughout their routes.
At some point, they formed a contract with Blood to guard the gates to his mansion. While the specifics of the contract are not clear, they seem relatively pleased with it.
Heart no Kuni no Alice / Anniversary no Kuni no Alice
When Alice first comes to heart they get ready to kill her but then stop and fall in love with her just like the rest of the people they call her lady and get mad when Elliot always talks to her
When Alice first encounters them at the Hatter Mansion Gates, they come close to killing her before Blood stops them. At first they seem to view Alice as a new toy, then a friend to show off their various toys to. Eventually, they start to try to become someone Alice can depend on, which draws them into conflict with each other. Alice has to decide if she sees them as potential romantic interests or as just little children.
Clover no Kuni no Alice
When the twins find her they are happy and call her Big Sis/Onee-san. In their single volume manga Bloody Twins, they enter the bath with her and scare her. At first Alice has no clue who the twins were and was scared to be with them but then they scare her more when she finds out that the older twins are really the same twins she has always known.
In the game, the twins often play hooky from the entertainment (the Assembly) and play in town. It is here that they reveal their ability to change their ages and they switch from young children to young men as they please. Alice has to come to terms with their viciousness as adults, as well as their innocence as children.
Joker no Kuni no Alice
Omochabako no Kuni no Alice
Diamond no Kuni no Alice
In the Country of Diamond, the twins are only adults. Their personalities are the same as ever, but they are far more uncaring towards Alice and do not smother her with affection.
- Alice in the Country of Diamond ~Wonderful Wonder World~ Anthology
- Alice in the Country of Hearts Theatrical Anthology
- Black x Gold
- Bloody Twins
- Futago no Koibito/Twin Lovers
- World of the Clover
- Alice in the Sleeping Forest Volume 1
- Anniversary no Kuni no Alice Deluxe Edition PSP Drama CD
- Anniversary no Kuni no Alice Pre-Order Data CD
- Anniversary no Kuni no Alice Quinrose Order Data CD
- Clover no Kuni no Alice Pre-order PSP Drama CD
- Clover no Kuni no Alice Quinrose Order Data CD
- Diamond no Kuni no Alice ~Wonderful Mirror World~ Deluxe Edition Drama CD
- Diamond no Kuni no Alice ~Wonderful Wonder World~ Pre-order Drama CD
- Drama & Comic CD ～Residence→Tower～
- Gekijouban Heart no Kuni no Alice ~Wonderful Wonder World~ Pre-order Drama CD
- Heart no Kuni no Alice Pre-order PS2 Drama CD
- Heart no Kuni no Alice Pre-order PSP Drama CD
- Heart no Kuni no Alice Quinrose Order Data CD
- Joker no Kuni no Alice Pre-Order Data CD
- Omochabako no Kuni no Alice Deluxe Edition Drama CD
- The Worst Amusement Park Drama CD
- Though they are featured in the musical, Dee and Dum do not have an ending.
Tweedle Dee and Tweedle Dum are seen running away from the faceless with Alice, who's tired. They jump off a balcony and kill the faceless that are after them. They walk to Alice and say sorry for scaring her and that they didn't want her to get killed and wouldn't do it again.
- While it is easy in the color scans of the mangas to tell the twins apart (when they are kids.) It is not easy in the black and white scans. The simple way to know is by the clover and heart that is on their clothes (and hats if you get a close up image). Dum's clover is on the left and the heart is on the right. Dee's Clover is on the right while the heart is on the left.
- Tweedle Dee and Dum see each other as a single entity, meaning that when they fall in love, they fall in love with the same person. However, this doesn't stop them from from having several differing preferences (like favorite color or ice cream flavor) and saying that they will fight to the death if Alice wants only one of them.
- It is mentioned by Crysta that the Tweedle twins are the only pair of adult twins in the Country of Diamonds. In other words, either the Tweedles are the only pair of twins in that time period or that there is another set of twins, only that pair must be just children (Alice in the Country of Diamonds only).
- The Tweedles have no cooking ability whatsoever.
- Both twins have a gift for clever and/or rude comebacks.
- While sometimes "Onee-san" has been translated as "Lady" (Tokyopop), it's literally "Older Sister," more commonly translated for this series as "Big Sis." The twins literally call Alice "Onee-san," so the latter makes sense... except when they're in adult form. It's possible that they're using it as a mafia term instead of "Anee-san."