I can't swear which one but it is in either Deke Meyer's Advanced tactics or in Kent Helvies Steelhead Fly Tying. I know I have seen it recently as well and these are the only two books I can think that I have picked up.
Sorry for the late reply. I hooked a great Skagit fish on one of Ed's Intruders when I was fortunate enough to join Andre to float the Skagit and Sauk with Ed a couple of years ago. I was not aware it was published in Dec's journal. Frankly, it's not one that is easily described! ;-)
Glad you found the info, I'll have to go look myself!
I discussed the intruder for about an hour with Ed on that float. I would have seen more of the fish Juro hooked if he would use reels without a silent drag. The intruder is not easily described or tied for that matter. I don't know Ed's thoughts to having the formula published as I haven't seen pictures anywhere other than Dec's S/S journal. Those pics should give a fairly accurate model to build from.
Premise for the intruder it invades your space, triggers some feeding reflex/reaction, and is tied large 3-5 inches in length. It is tied in two segments with a dubbed sparse body. Both segment have "boo" and a hackle in front of the "boo". Pretty simple when you look at it.
If a bunny leech is like a streetwalker in a tacky leather jacket when compared to your more civilized han-hacked matuka , then you can probably visualize the Intruder as a steriod-enhanced wolley bugger having a Very Bad hair day and not be far off!
Guys who like to fish small flies might want to steer clear of this one! <g>
Can't recall the issue but one of the last few issues of the "old" Wild Steelhead and Salmon mags has a pictiure of Ed Ward, a steelhead and a tube fly that just might be an Intruder. Hang on, let me look it up...
[5 minutes pass as Dana rifles through his magazine pile]
...okay, I have it--page 12 of the Spring 1999 issue (Dec is on the cover preparing to beach a chromer). The tube is pretty big and looks similar to the one pictured in Hogan's Skagit Journal book, but not exactly. No matter--it's a B-I-G fly, certainly an intruder, whether it is THE fly or not!