Laughter
Darius Pike was surprised that a Jixen was capable of laughter. (TV: Hound of the Korven)
Having used the Immortality Gate to transform the human race into what he called the "Master Race", the Saxon Master laughed out loud in front of the Tenth Doctor. He was joined by numerous members of the Master Race, including Trinity Wells and Barack Obama. (TV: The End of Time)
The Lady Cassandra O'Brien.Δ17 avoided laughing as it gave her "laughter lines". (TV: The End of the World)
Rhys Williams recalled that he had his first kiss with Gwen Cooper in supermarket; they were in a queue when Rhys told her that he did not want to make spaghetti bolognese as he could not kiss her with "garlic breath", upon which Gwen laughed, called him "Rhys the Rant" and kissed him right there in the queue. (TV: Adam)
The Twelfth Doctor thought that Robin Hood and his Merry Men laughed too much. Though Clara Oswald initially doubted this, she recognised that the Doctor was correct, Robin using his laughter to cover up his worry about the fate of Maid Marian. (TV: Robot of Sherwood)
The Ninth Doctor violently laughed at Big Ben just after Christmas 2004, mentioning to Lee that he should "make the most of it while you can". (PROSE: Have You Seen This Man?) On 6 March 2006, the Big Ben would indeed be heavily damaged by a Slitheen craft. (TV: Aliens of London, etc.)
Other realities
In Pete's World, the Tenth Doctor and Rose Tyler witnessed a street of people erupt into laughter after their Cybus EarPods downloaded a joke to their brains. (TV: Rise of the Cybermen [+]Loading...["Rise of the Cybermen (TV story)"])
Daleks
Laughter was rare among Daleks, to the point that early on in their history, the Daleks in the Dalek City had never heard laughter and were scared of the sound. (TV: The Daleks, COMIC: The Message of Mystery) When the First Doctor and his companions returned to Skaro, they were confused by a laughing Dalek before its operator was revealed to be the Thal Boden playing a tasteless joke. (AUDIO: Return to Skaro) Some time later, when Jeff Stone visited the Dalek City covertly, however, he heard a room full of Daleks laughing upon learning that some humans were so self-centered as to believe humanity had invented the Daleks. Stone found the sound very unpleasant. (COMIC: City of the Daleks)
During the Last Great Time War, the Dalek Time Strategist laughed at the Eighth Doctor's offer to return N-Space to what it was before the conflict, interpreting the statement as the Doctor admitting that the Time Lords could not halt Dalek conquest. (AUDIO: Restoration of the Daleks) After the Battle for the Tantalus Eye, a Dalek of the Eternity Circle laughed at the War Doctor. (PROSE: Engines of War)
Following the Time War and the rise of the New Dalek Empire, Dalek Caan repeatedly broke into laughter after he had broken the time lock and seen all of time and space, an experience which had seemingly driven him insane. (TV: The Stolen Earth/Journey's End)
A Reconnaissance Dalek laughed at the Thirteenth Doctor and Team TARDIS, a sound so raspy and off-putting that it took a moment for the humans and Time Lord to recognise it as laughter. (TV: Resolution)
Behind the scenes
In non-valid sources
The Fifteenth Doctor, standing by his jukebox, once excitedly stated that there were only two days left to go, and laughed. (TV: Untitled (episode 2) [+]Loading...{"noital":"y","ep":"2","1":"Untitled 2 (May 2024 TV story)","2":"Untitled"})
