- ''For the manga publishing company, see BLU (company)
Blu (Bidu) is a character in the Monica's Gang comic strips, created in 1959. He was the first character created by Mauricio de Sousa, along with his owner Franklin (Franjinha). This blue dog appears in the logo of Mauricio de Sousa Produções, the company founded by Mauricio to release his works. Maurico says he based both Blu and Franklin on himself and Cuíca, the dog he had when he was a child. Blu doesn’t have his own printed comics, but when he completed 40 years of existence, a special print was released for him, and titled "Bidu – Especial 40 Anos" (Blu – 40 Years Special).
Blu is the only character who appears in two different kind of stories. In one kind, he is a normal dog, owned by Franklin, who fears taking baths (but is invariably forced to take them by Franklin), does anything in exchange for a bone, and plays around with the other dogs from the neighborhood. In the other kind, he is a director/actor of comics, is totally personified (walking by two feet behind the sets, and walking like a normal dog when acting.) and is famous for the strips in which he talks to objects.
- Franklin (Franjinha) – The brains of the gang, and the only character who is related both to Blu and to Monica and her friends, apart from Duke. Near his house, he has his own laboratory, where he spends hours, or even days concentrated on his chemical experiments, which always end in failure. He’s also an inventor, building up complex machines like time machines, teleporters, robots, and many more. He is completely in love with Marina, the artist of the gang, even though she has no interest in him.
- Duke (Duque) – Blu's best friend, appears mostly on the stories in which Blu is a normal dog.
- Glu (Bugu) – Not exactly an enemy, but Blu’s worst friend. He loves to give Blu a hard time, by begging him to take part of his strips. Blu never accepts, so Glu sees himself forced to perform his famous “imitations”, even against Blu’s wills. However, in the end he is always kicked off the strip (literally). He is famous for saying “Alô, mamãe!” (Hello, mommy!) when entering the strip, and “Tchau, mamãe!” (Bye, mommy!), when being kicked off. He has also appeared as Mister B (a clear reference to the magician Mr. M), a great magician who everybody thought to be Blu.
- Manfred (Manfredo) - Blu’s main assistant. Appears only on the strips in which Blu is a director/actor. He is a secretary, producer, and arranger. He is never seen without his cap on the head and his clipboard on the hand.
- Dona Pedra (Mrs. Stone) – The most famous object that talks to Blu. A single grey stone, which cannot move. Her philosophical conversations with Blu became famous among Blu’s readers.
- Zé Esquecido – As his Portuguese name suggests, this character suffers from amnesia, affecting his Short-term memory. He also can’t remember basic things like closing the eyes when sleeping.