Anyone who has played the Halo series knows the explosive bliss of the SPNKr rocket launcher. When you find one, you have nothing to fear from a squadron of enemy Wraith tanks or Ghost bikes--they now fear you.
One hardcore fan, YouTuber Nick Brick, constructed this 24-lb replica rocket launcher from several thousand Lego pieces over the course of three months in 2016. The build is fully functional with a removable dual launch tube. The only thing it doesn't do is actually fire rockets. Still looks mighty sweet, though.