I can't really think of one...although I do think that I don't really have that good of a use for those little spikes on the Ben 10 figures.
(excluding broken pieces)
Those huge semi-trans Vahki head wraps.
And those Toothbrush Mask attachment things are hrad to use.
Either way, I wish these came in more colours and were in more sets; they aren't as thorny-looking as the traditional spike pieces that current sets have and would provide more options for detailing
Speaking of Ben 10, I would like to see someone use this effectively
Sparkytron did it, albeit he did have to flip it inside out.
...is that supposed to be a spaceship?
Yeah, it's a really awkward piece. But most of the other launchers can't be used as much other then launchers either...
MOC by JANGBRiCKS
What pieces exactly?
Well, I didn't say they were impossible to use. Just that they're hard to use.
I dunno if those would technically count. They're probably not made out of ABS plastic in an official LEGO factory.
This figure is comprised of a disturbingly large quantity of useless parts.
Those little rubber-band holder pieces that came with the Visorak and other BIONICLE sets.
it seems I hold the displeasure of owning him..
At least you got Vapour; he's pretty cool.
Bohrok bodies are too weirdly shaped, textured, and clunky to be used nicely
honestly, I haven't used a single Vapor specific piece either.. worst exclusive set evar should have gotten Rotor instead
on a side note, I'm making a list of all these to see how many I can actually use In a single MOC
From a cereal box:
Yeah, that one's supposed to be a more alien one in design, I made another that looked less geary, and more like something humans would build, but I took that apart because I needed the Roborider head for a MOC contest.
I can think of one instance this is used in: He makes awesome creations, and he uses parts in very unusual way.
Rahiden made a spaceship, only using 6 or 7 pieces, one of these is the aforementioned squid launcher.
I feel like if I post a piece someone out there made something to prove me wrong.
Hmmmm, I think the most useless part would be stuff from Galidor.
The Vakhi piece the head attaches to, that then attaches to the Rahkskii piece. I know it can be used for stuff, but it's quite difficult.
I have him as well and I can concur with you
Probably this...believe it was used with the Bohrok (Maybe the Rahkshi also, not sure) had so many ideas for it originally yet it can only really connect with a few pieces and it can only be hung from the interior of a canister. I suppose if you are good with pieces you could probably use it as a peg-leg or a spine piece, but cant think of much you can do with it.
They make nice wings.