Sticks and stones

short bus
special bus
special
retard, retarded
spaz (which references spasticity; apparently the term has become so entrenched that the origin is no longer widely known)
cripple, gimp--though a friend is helping me understand that it is like the n-word and some within the community are reclaiming it through transformative language, much as our friend Dan Keplinger has done with his title of King Gimp. (As Dan states in the film, gimp also means "fighting spirit".)
wheelchair kid, wheelchair as descriptor for a person who uses one, wheelchair-bound or wheelchair-confined, or anything else that suggests the person is a Transformer and this piece of assistive technology is an actual part of their body
helmet-head
whack-a-doodle, casual reference to a need for meds, any slang reference to mental illness, or reference to behavior that suggests mental illness
I'm sure there are more, and maybe I'll add to this list. And I know it is usually better to speak from the positive perspective, as in "use these words instead", but I'm stacking them this way for a reason. Because these are the words, terms, sentiments that Sekai heard--or worse, felt--over and over and over. So the next time you think using one of these terms is funny, please stop and ask yourself, which aspect of Sekai's being, or that of any number of people who have disabilities, do you find hilarious enough to use it to mock someone else?
This is not a rant. It is a heartfelt plea from a mother who watched these words cut her son down to the point where he felt like there was no place in this world for him.