Animation Appreciation Refuge Thread #1

Now in /carcom/ due to spam

The Sakuga Wiki [JP] - http://www18.atwiki.jp/sakuga/
Good Animation Blog - http://www.pelleas.net/aniTOP/
Other websites: http://pastebin.com/r2Vcy4b2

Animation on Twitter, Tumblr and Youtube:
http://pastebin.com/CQa8wU3q

Older Threads: #1-#10-2 http://pastebin.com/474RAqxr

http://i.imgur.com/O4M8mFy.gif

I know you guys most probably have seen this Bebop/Naruto .gif many times before, but can someone explain what exactly happened here? I keep reading so many stories as to why they look the same, but I figured it's best to clear this up here. If I'm not mistaken, the top is Yutapon's animation, but who did the one at the bottom?