Danny Pink
Rupert "Danny" Pink was a sergeant in the British Army, who later became a mathematics teacher at Coal Hill School.
Biography
Childhood
As a child, Rupert lived in West Country Children's Home in Gloucester for some time. He disliked his given name and wanted to change it to Danny when he got older. One night, he had a nightmare of someone under the bed grabbing his ankle, and he met the Twelfth Doctor and Clara Oswald for the first time. They encountered a figure which the Doctor believed might be a creature that hid under the bed. The three of them turned their backs so the creature could leave unseen. After it departed, Clara attempted to put the child at ease by placing toy soldiers to guard under his bed. She designated one of them — which Rupert had called "Dan the soldier man" — as the one in charge: a soldier so brave, he didn't need a gun. Rupert's mind was then scrambled by the Doctor to prevent remembrance of this encounter. He instead would only recall a dream where he was "Dan the soldier man". (TV: Listen)
Military career
Later in life, Rupert started going by the name Danny and joined the army, where he performed a number of humanitarian tasks, such as building wells, alongside traditional military work. (TV: Listen) He was a sergeant and served five years both at home and in Afghanistan. (TV: The Caretaker) Following his exit from the army, Danny became distressed when mention was made of him having killed while a soldier. (TV: Into the Dalek)
Maths teacher and relationship with Clara Oswald
Despite leaving the army, he established the Coal Hill Cadet Squad when he began working at as a teacher at Coal Hill School. It was here that he was introduced to Clara Oswald by Mr Armitage. She invited him to join her at Kathy's retirement party after work that day, which he initially declined — an act he immediately regretted. While reviewing this awkward moment to himself, Clara overheard him. Although this further embarrassed him, Danny gratefully accepted her offer to grab a drink together. (TV: Into the Dalek)
The two went for a drink at some point later, with mixed results. The couple argued several times, and Clara left twice. After an adventure with the Doctor, Clara came to Danny's flat later that night, and, after the two apologised for their behaviour, they kissed for the first time. (TV: Listen)
Despite these difficulties, the two continued dating. They attempted to set up a date and share a kiss in an empty classroom, but were interrupted by a nosy student, causing both of them to scold, "OUT!" (TV: Time Heist) Clara, however, continued to have adventures with the Doctor (PROSE: The Crawling Terror, PROSE: The Blood Cell), which led to him being puzzled at Clara's occasional discombobulation, including one incident where he found her wearing a space helmet for some reason (TV: The Caretaker).
Afterwards the Twelfth Doctor re-met Danny Pink as an adult, insisting that he was a PE teacher even after Danny said he was a maths teacher. The Doctor was not unaware that this was the same individual he met as a child (Danny did not remember him due to the Doctor scrambling his memory of their first encounter).
After learning the truth the Doctor and Clara's exploits, Danny warned Clara that he wanted her to stop lying or it would spell the end of their relationship. He had also met men like the Doctor before who pushed people to get stronger. Because one pushed him too far and made him do something he regretted, he told Clara to promise her that if the Doctor broke her trust in him and did something similar, that she would immediately go to him for help. (TV: The Caretaker)
Legacy
Eventually, he became the great-grandfather of Orson Pink. (TV: Listen)
