This is a list of parts of Pokemon that are not connected, but may be able to potentially come off, even if it isn't show in it's sprite.
Parts that are not connected:
Haunter's Hands
Exeggcute
The things near the bottom of Cryogonal
![Cryogonal](https://img.pokemondb.net/sprites/black-white/normal/cryogonal.png)
Probopass's mini noses
Shedinja's halo
Klinklang's rings
Porygon-Z's head
Claydol's arms
Hoopa Unbound's arms
Hoopa's arms
The back of Rotom Mow form (Note: I think it is not connected, however it is hard to tell.)
![Rotom Mow](https://img.pokemondb.net/sprites/black-white/back-normal/rotom-mow.png)
Parts of Gastly's body (Because Gastly is made of gas, all of that not connected purple stuff is still Gastly)
![Gastly](https://img.pokemondb.net/sprites/black-white/normal/gastly.png)
The rocks around Mega Steelix
![Mega Steelix](/pokebase/qa-plugin/https-img-proxy/image.php?key=ccf4722b1b0ec4a3&url=http%3A%2F%2Fi46.photobucket.com%2Falbums%2Ff117%2Fnoobiess1%2FMegaSteelixfinished_zps202957cd.png)
Duskull's eye orb
Parts that may come off, but aren't shown to:
All of the Pokemon shown here.
The seeds on Sceptile's back.
Magneton
Dugtrio
Tropius's bananas
That's all I could find.
Hope this helps!
Source1 (I just scrolled through the list.)
Source2
Source3