Here is a brief history of April Fool's pranks deviantART has played on it's members. Please note that information is still missing (mostly older years) - this is because some April Fool's pranks were never recorded or are lost in the millions of journals on the site.
2001 - "jark is Arrested"
jark is arrested in Disneyland for cutting in line and refusing to move to the back.
2004 - "British Takeover"
April Fool's Day 2004 marked the day the British took over deviantART. New rules were enforced on that day, including spelling "color", "colour" and saying "Cheers guv'nor" instead of "Thank You".
"Please note that any American who uses the term "soccer" will have their IP banned from deviantART and their gallery purged. Not only that, but the last 10 people who have commented on that American's user page will also be banned. Let that be an incentive for you Americans to refer to the beautiful game as FOOTBALL and not "soccer". No exceptions will be made."
- devart received the Deviousness Award.
- TheInternet received the Deviousness Award.
2007 - "Changes to the Help Desk"
This year sparked changes to the Help Desk, specifically, it was going to be a subscriber based service. Non-subscribing members would need to pay $29.95 per year to have access to the Help Desk, a reduced price of $19.95 was made available to deviants who only wanted live help.
2008 - "Mudkips"
This day was the day of the Mudkips (a Pokemon). User's icons were changed to this icon made by Chimpantalones.
Deviants could not change their icon back until April 2nd. As well as the icons, Mudkips received the Deviousness Award.
2009 - "Symbol Changes"
Symbol changes were the main prank for 2009's April Fool's Day. All $taff Members, `seniors, ^gallery moderators, and MNs were given the ! (banned/deactivated) symbol.
Beta Testers got a unique symbol change by receiving the snowman symbol. ☃
Other pranks this year included icon changes and upside down text across the site.
2010 - "Team Gaga/Edward/Jacob/Seeker"
Team Gaga. Team Jacob. Team Edward. Team Seeker. All icons were changed to one of these teams, and each team has three different avatars. Again, users could not change avatars until April 2nd, and could not "swap teams".
Here are the icons:
Team Gaga (Lady Gaga)
Team Jacob (Twilight Saga)
Team Edward (Twilight Saga)
Team Seeker (Legend of the Seeker)
But clearly, Team Gaga was the best. LadyGaga also received Seniority and the Deviousness Award on April Fool's Day that year.
Llama Badges were also launched on this day!
2011 - "A Trollface April Fool's"
Trollface was the theme of 2011's April Fool's Day with Trollface himself appearing throughout user's message centers and deviation pages. trollface also received the Deviousness Award.
Several Trollface T-Shirts & Gear were made available in the deviantART shop until sold out.
2012 - "Feline Overlords Takeover"
MajorGeneralWhiskers, leader of Feline UpRising (FUR) had taken over deviantART and kidnapped deviantART's mascot, Fella. Deviants had to submit 15,000 cat-related deviations to the Free Fella gallery to save Fella from the Feline Overlords. Fella was freed a few hours after the takeover. Anyone who helped free Fella was awarded the Whiskers profile badge.
MajorGeneralWhiskers received the Deviousness Award on that day.
Among the Free Fella movement, was cat-related facts popping up throughout the site (see below)
When browsing, some thumbnails were changed to cat-related images (but changed back after hovering).
2013 - "deviantHEART.com"
deviantART.com had released a new dating website for artists, deviantHEART.com.
Deviants who took part had to take a short survey about what they are "looking for" in a partner.
The answers did not influence the results at all, because each deviant's perfect match were randomly generated.
That concludes the history of deviantART's April Fool's Pranks, until next year!