What are, famously...
Within, without, ubiquitous
Swift and slippery, not to be trusted
The mysterious things in question are
Heffalumps and Woozles, from Disney's version of Winnie-the-Pooh.
They're black, they're brown, they're up, they're down
They're in, they're out, they're all about
They're far, they're near, they're gone, they're here
They're quick and slick, they're insincere
Be a very wary bear
Incidentally, "famously" is overstating it, at least so far as my state of knowledge goes. I had never encountered
the song in question (being unfamiliar with Disney-Pooh) but noticed the brown/down and near/here rhymes and went a-googling (first guesses: nursery rhyme, Dr Seuss, of course no luck with either; but putting in "black brown up down far near there here lyrics" did the trick.)
Sorry I didn't watch that movie and I know it has been answered but a rough answer could be
Within without ubiquitous
Rocks are almost every where on the earth inside and outside
Many meanings . It might be distance.
In some area they are present and other not
Swift can be there slope and slippery sure they are
Not to be trusted
Accidents happen on mountains