Answer:
Other terms for this handy device include doohicky, doo-dad, and whatchyamacallit.
Defends your noggin from the hard pavement
Long and thin, red within, with a nail at the end.
This type of corn swells up and bursts into a crisp puff when heated.
When it's dirty this should never be aired in public.
A mysterious, fantastic creature, It has one defining feature, And for humans at their worst, In their eyes it's just a horse