What is Farfetch'd?
Farfetch'd is a duck Pokemon who holds a leak as a weapon.
Tell me more about Farfetch'd
Farfetch'd suffers from the reverse problem of Tropius in that it doesn't have any other evolutionary forms. The problem is that it's so weak and small that there's no reason why it shouldn't evolve into something more powerful. Let's take a look at a few other similar Pokemon who do actually evolve:
Psyduck is also a duck Pokemon. When it gets strong enough it gets to evolve to the more powerful form of Golduck. Why should Farfetch'd be the only duck Pokemon who doesn't get to evolve.
Farfetch'd is similar to Cubone in that they both use weapons. Cubone uses a bone while Farfetch'd uses a stick. If Cubone gets to evolve then Farfetch'd should evolve too.
In case you want to use the argument that Farfetch'd is just too common-looking and not the owner of any traits that deserve a higher form we can look at Wingull. Wingull is just an ordinary Seagull Pokemon. Seagulls are dull and boring yet this guy gets to turn into a pelican when he gets strong enough. I think Farfetch'd should be able to evovle into something like this Mandarin duck: