here's a link to making a popper, 'tube fly style':
[url=http://flyforums.proboards53.com/index.cgi?board=flytying&action=display&thread=114 4691082:16c39]http://flyforums.proboards53.com/index.cgi?board=flytying&action=display&thread=114 4691082[/url:16c39]

btw, a 'scoobi' is a hollow soft plastic cord like larva lace used by kids to make knotted stuff.