.Mac. said:

These arachnids appear a bit large (twice the height of yoda?) and menacing though, so inserting them somewhere without disrupting the focus on the character(s)/scene is greatly limited. I'm interested in seeing these arachnids, but I feel it'd only work at the long-shot of the X-Wing crash and/or maybe while R2 is out in the rain.

"In addition to the very large ones, there were also some smaller, knee-height ones; Luke Skywalker ended up facing a number of these in his training.["

http://starwars.wikia.com/wiki/Knobby_white_spider#cite_note-RS_III-0