There's no velociraptors in Shakespeare!

Particularly you, butterflybill and sayyana. I'm having yet another latin word construction quandary. I'm wondering, first of all, how to construct a word for "the little swift men," from maybe either "celer" or "rapidus." I've been wrestling with diminutive plural suffixes all morning, and it's driving me crazy. I have a hypothetical "celerilli," but I'm sure that's wrong somehow. The second part of my problem is, when I finally have this crazy ass word made, how the hell do I decline it?