Notes:

My edit based on the above GIF, using my Bipper remake shown below of this template of Dipper from this promo for the upcoming episode "Dipper and Mabel vs. the Future".

Background images:
(you can go to ezgif to split it into frames, slow it down, etc.)
September 11, 2001 attacks on the World Trade Center
-frame 150 of the Zapruder film of John F. Kennedy's assassination
-atomic bombing of Hiroshima
-security footage of the Columbine High School shooters
-the Hindenburg disaster
-R. Budd Dwyer before committing suicide live on TV
-Willy Stöwer's painting "Sinking of the Titanic"
-Space Shuttle Challenger explosion
-an Islamic State/ISIS/ISIL group in Anbar Province, Iraq
-the goddamn ball pit at DashCon 2014
-this Pinecest art (kind of NSFW; not p--, but close) by Tumblr user doublepines