R5-D4 [1995, POTF2]

...with CONCEALED PHOTON MISSILE LAUNCHER.

WTF. Really, WTF? A concealed photon missile launcher? In a droid. In a droid that we saw for a few minutes in the first movie that broke down on Tatooine and never posed a risk to anyone? That droid?

I apologize for the quality of the graphic showing how the photon missile works, but you get the idea. Apparently, this made sense to someone, and that R5's continuity could be compromised in a way that R2-D2's couldn't. Instead of a faithful figure/collectible, R5 became a joke.

Five reasons to get this figure:

1. Get it because everyone else doesn't want it - so hipster.

2. For a full examination. What is going on here? What are those rods on the sides of its legs? What is going on!?

3. Admit it - with the vintage R2 you used to pretend he could shoot out the bottom. This is just a realization of that impulse.

4. A great accessory for desk wars.

5. Now, we droids will have revenge on our oppressors! Torpedo all Jawas!

Backstory:

R5 was built by the Industrial Automaton company. The R5 line was notorious for being low cost and low quality, and R5-D4 was no exception. He went from owner to owner before being sold to the Jawas and turned down by Luke and Uncle Owen because of his bad motivator.

R5 was stolen from the Jawas and sold to a member of the Rebel Alliance. He was refurbished to much better working condition and set in place in Mos Eisley for gathering intelligence. A humorous short–story posed a different theory: that he could use the Force and foresaw that only R2 going with Luke would save the galaxy. He thus blew his own motivator.

In the movie Luke says, “This R2 unit has a bad motivator.” Whether Mark Hamill the actor, the character Luke, or the scriptwriter was mistaken is under debate.

Want more? His Wookieepedia article