I have a girl wanting this for her husband's bday.  The cake is going to be small, like 6-7".  The "5" is the most important, but would like as much of the rest as possible.  Here's where I'm needing some help.  How would you guys go about it?  I plan on doing the 5 in fondant & thought royal for the smaller lines.  But some of the detail throws me for a loop and what would be the best way of doing it...like the black widow? I thought cover in blk fondant & just laying the cream fondant cut outs on the blk and hand painting the spider web lines and the spider.  ANY thoughts are greatly appreciated!!!

AOnce you lay the web cutouts make a fondant black spider with the little keyhole and put it on top. Looks very detailed so if it were me I would trace the hard parts by laying wax paper on top anduse an exacto knife to cut it out. That way you have a pattern for the fondant. You could easily tape the wax paper to the helment

I agree - trace out the patterns on paper first, then cut out the shapes in fondant and place on the helmet.  Or pipe as much of the designs as you can if you have a steady hand.  This is a picture of a helmet that someone I know made, I am sure if you contacted her through her Facebook page she would be happy to give you some tips.

I didn't think of cutting things out on wax paper first.  I guess scaling it down will be the hardest thing :(.  I am really dreading the small details of this cake and I just can't put it all on a 7" cake

I would get the biggest, most important details on the cake first, like the number and the web, etc, then fill in the empty space with other details that can fit.....I agree some things will be left out, look at the helmet and make a mental note of parts of the design thta can be sacrificed due to the size.