I'm sure all the furries here will love this idea. I got the idea while I was browsing the forum because of all the furries here, and because I'm into pegging (women doing men with a strapon) and have been thinking about getting a "strapless" strapon for just such occasions. I'm not into dressing furry myself but I love furry art, especially the dickgirl/futanari furries. A strapless strapon, fyi, is sort of a double-dong dildo with a retention bulb for the vagina/anus (usually placed to hit the G-spot/prostrate) of the wearer, or Top, on a curved 'neck' leading to the main dildo to be used on the Bottom.
Here are some links to the 3 examples of these that I'm aware of -
The Feeldoe,
The Nexus, and
The Share XL.
They all have variations, but frankly, I'm a size freak (even though I can't take anything wider than 3") and even the biggest versions of these don't excite me much. (although, the ridges on that Share XL make me drool) So, as I was looking at the 'Suggestions' threads here and thinking about yiffy play, I thought "Hey! Zeta could do it!".
And then I thought that there could also be one made for the guys to wear over their penis & balls, like a PPA, and could also serve as a masturbation sleeve. And either of them could be worn with furry costumes, with holes cut out in the appropriate spots, without an annoying and chafing harness showing. And, done with balls and the natural coloring, the visual effect would be spot on.
So I whipped up a couple of rough images to illustrate the ideas and they're attached below. I based them on the Akita since it's a model that's already thick enough to have room inside for a human penis, although I suggest a smaller knot so that these are usable by more people for tying play, and a great number of furries are canines. Of course, these can also be made in equine, feline, etc., etc.. You could call them "The Yiffy Line".

The pictures are pretty self-explanatory and I include text on them about various features and ideas. But I forgot to mention something about the guys model. It may be obvious, but I'll mention it just to be sure it's clear. The guys version should be molded in a contracted state, along the shaft (including the knot) where the tube is on the inside, so that it expands to the normal size when an erect penis of average girth is inserted.
The idea for the internal slanted ribbing is kind of like the inverse of the ridges on that Share XL dildo, for stimulation during solo or partnered play. I guess the tube should be about 7.5 or 8 inches long from the very back of the toy for those of us more blessed than most. (I'm 6.5" max along the top on a good day) The back of the guys version would have a hole to insert the penis and balls through which will behave as an erection ring and hold the toy in place without a harness, about 1.5" in diameter, I guess, since the silicone will stretch. (I just learned recently that my size for a metal cockring, behind the balls, is 2" inside diameter) Or maybe that could be a custom choice for smaller or larger guys.
Note: Metal cockrings have to be put on while soft but this would probably be easier to slide on while erect, popping the balls through while stretching the hole open. The men's version could also be used like a regular Zeta toy with an average sized human-style dildo plugging the tube. Maybe Brown Bear could make one for his human line that will plug it perfectly.
OK, enough already. The pics explain the rest.
BTW, BB, I'm unemployed at the moment but once I have a good job again I would definitely be willing to do that investment/preorder deal on these models. I'd love to have (both the guy & gal versions of) these in a canine & a (2.5" dia. flare & ring, 10" long) equine. Also dragon, gryphon, and maybe a tiger without the bend. (Does that seem greedy? LOL) Thanks for taking our suggestions, BB.

Dar