Blizzard Outcasts
http://us.blizzard.com/en-us/games/outcasts/

Pajamathur
http://www.heroesofthestorm.com/en-us/news/13593522/pajamathur-hero-spotlight

Herald of the Stars
http://us.battle.net/sc2/en/blog/13611763/hitting-on-the-selection-of-a-name-4-1-2014

Happy Reaper
http://us.battle.net/d3/en/blog/13607363/ascend-to-victory-with-happy-reaper%E2%84%A2-4-1-2014

WoW 6.0 Patch Notes
http://us.battle.net/wow/en/forum/topic/12371977139?page=1

Artcraft - Remaking the Female Draenei
http://us.battle.net/wow/en/blog/13474198/artcraft-remaking-the-female-draenei-4-1-2014

Post has been edited 2 time(s), last time on Apr 2 2014, 2:00 pm by Oh_Man.

Also, the WoW 6.0 patch notes:
http://us.battle.net/wow/en/forum/topic/12371977139?page=1

And the source code for Herald of the Stars has an easter egg.

Is that the big asci art of Blizzard? Or was there something else?

Those were actually pretty good

http://us.battle.net/wow/en/blog/13611769/april-fools-4-2-2014