He was offered a place at the University of Dundee to study history, but decided to take a gap year to see if he could make comedy work as a full-time career.

[2] When Sloss was sixteen, he was put in contact by his mother with comedian Frankie Boyle, who performed at a conference she was attending.

[citation needed] In 2015, Daniel wrote and subsequently performed his 7th show at the Edinburgh Festival Fringe DARK.

[18][19] On 25 October 2023, Sloss opened for The Mighty Nein Reunion: Echoes of the Solstice, Critical Role's live show at OVO Arena Wembley where the cast reprised their characters from their second campaign.

[20] He was the first stand-up comedian to perform on Channel 4's The Paul O'Grady Show (2009) and was commissioned by the BBC in April 2010 for a broadcast sitcom pilot, The Adventures of Daniel, which transmitted on 23 August 2010.

In January 2011 he performed on ITV1's Jason Manford's Comedy Rocks and in March 2011, was part of the BBC's Comic Relief marathon online broadcast with David Walliams called 24 Hour Panel People, as a panellist on Mock the Week.

[22][23] The following year, Sloss featured on the BBC's Stand Up for Sport Relief performing a set as well as coaching heavy weight boxing champion Tyson Fury for the latter's stand-up comedy debut.

[24] In September 2012, he recorded a TEDx Talk in Ealing and performed on Set List: Stand-up Without A Net for Sky Atlantic, alongside an all-star lineup of US and international comedy alumni.

[26] In addition, Daniel signed a talent deal with Conan O'Brien's production company Conaco to develop his own shows.

[27] Along with a number of fellow comedians, including Kai Humphries and Tom Stade, he wrote, co-produced and starred in 6-part internet sitcom M.U.F.F.

[28] In the first half of 2017 he featured on Comedy Central's Drunk History re-telling the story of William Wallace (portrayed by Keith Allen) as well as the Dave Channel's Dara O Briain's Go 8 Bit.

[34] Sloss' hobbies include gaming, watching Robot Wars (in which he appeared as a member of the Bot Out of Hell team in 2002) comedy films, and playing football.

[35] He has several tattoos such as a portrait of Nikola Tesla, cartoon tigers drawn in the style of Calvin and Hobbes, a picture of Anthony and the Aardvark, and an image of the Joker.