Barbaracle's limbs are said to not always follow its head's orders. This is because its limbs are barnacles, too, and not actually limbs.
"Wobbuffet" is actually the tail, the big blue thing is a dummy (a wobbly buffer) to protect the 'tail'. This is why it can't directly attack.
Diggersby's ears resemble diggers/construction machinery.
Cubchoo's runny nose becomes Beartic's icicle beard - it even begins from its nose.
WTF AT WOBBUFFET