this is a foam jig hook. the body is soft.
design the tail. where would you put rubber legs?
I might try threading the legs through the body on a needle, tail just a little marabou probably black or chartreuse.
Eric
That thing wants to be a perch! Get some orange in there somewhere! 
I’ve used those before and tied them just as Eric said with a short marabou tail and sewn in legs , right in the middle.
Those things are sold as walleye jigs to suspend bait.
You can get them in several shapes as well.
I’d forgo the rubber legs and use some bucktail and hackle feather tips for the tail. Maybe a couple strands of Krystal Flash…hmmm…
Buddy
Depends on how you wanna fish it or what you want it to look like.
If this is for a topwater to mimic a struggling bug, then I’d choose rubber legs, and maybe some hackle to go with the marabou tail.
If you want to use this to mimic a minnow fished a foot or so above the bottom with a sinking line, then I’d do like Buddy suggested, and skip the rubber legs, but still go with the marabou tail.
For an insect replica, through the foam.
For a minnow replica, start above the bend and try adding in this order. Krystal flash, maribou, rubber legs. The rubber legs would snug up to the back of the foam.
For a frog replica put legs through the foam then ALSO at the back.
From looking at it, it looks like a large size hook, I would not add any legs to it. It looks to me like it would ride low in the water and I would just add a tail made from buck tail and fish it as a slider for smallmouth bass. Due to it’s shape, it will not “pop” or make a lot of noise and would, in my opinion, make a better slider than popper.
The only thing I would do differently than what others have already suggested is that I would use Arctic Fox body fur for the tail or even rabbit fur. I find that while marabou has terrific action in the water, the tail on a minnow pattern really doesn’t move that much and the marabou is rather fragile and breaks off too easily. Just one man’s opinion.
Jim Smith
What a great looking fly.
Is the colour spreyed on?
How do you do the vertical lines?
How do you form the foam?
Thorarinn.
I tried one of these. Here is my 1st one:
It did not float. I wanted the action of a slider…but it sank slowly. I added a strip of foam & now it works great!
Brannon
Tail: Swish Tails http://www.dougswisher.com/fly_tying_materials.htm
Body to tail joint: rub-a- dub dubbing http://www.dougswisher.com/dubbing.htm#Fly Tying Dubbings
somebody in a factory makes them so i have no idea
Looks like a size 1 or 1/0 hook?
Neck hackles for the tail(legs) 3 each on each side with the cupped (con-caved side) out). I chartrues between 2 black on each side. Then wrap 2 hackles (1 of each color) around the tie down for the legs like a skirt. Maybe a couple strands of krystal flash on each side as well. Then thread some rubber/silicon strands just behind the first black stripe behind the eyes and you’d have a nice frog pattern.
Ok, I’m going to bed now, this will all be gone tomorrow.
sweet dreams!