The second thing I thought after I saw District 9, right after "holy shit", was "man, I hope they release action figures for that mech". Sadly, we're a few years on and that hasn't happened, but where official merch is found wanting, custom builders can get the job done.
Built to "GI Joe" scale (so 3 3/4 inches), artist Chris "Sabretooth" Hooton made four figures, one for Wikus, one for Christopher and his kid, and one for the mech with the pig cannon.
What's awesome is that while Wikus and Christopher are "heavily modded" versions of existing figures, the other two were built from scratch.
DISTRICT 9 CUSTOM ACTION FIGURE SET 3 3/4" 1:18 SCALE [Sabretooth, via Super Punch]