He told me if I ever found more superhero fleece to let him know, and he'd get another one. Well, I found a few new Batman and Superman prints, and I sent him pictures, and he picked black Superman fleece. He also requested booties and a chest pocket.
I had drafted fun fur boots for Karen's Lion Costume a couple years ago, and I used that pattern as a guide for the booties. 
This is my pattern for the booties. I had to make the toe section shorter, and I traced around some of my husband's shoes to make the feet. I cut the feet bottoms out of leather and lined them with fleece.
Here starts the tutorial. Bear with me, as I've never done this before. I'll just try and talk you through the steps as best as I can. Note: This is just a supplement to the instructions in the pattern. These are my tips for the zipper, ribbed cuffs, and ribbed neckline. The only thing I would do different from the order laid out in the pattern instructions is to sew the center front seam and zipper first. The instructions have you do them much later in construction, when most of the onesie is assembled, and it doesn't make much sense. This is way easier.
As for general construction, I sewed all my seams with my serger. The only seams I reinforced with stretch stitch were the center front, center back, and anything with ribbing attached.
This is the center front seam. For all my seams, I have my pins spaced about every 4-6".
Place your zipper on the seam so you can mark the bottom of the zipper stop. For most cases, you can have the top of the zipper flush with the neckline, but in this case, I'm only taking a 1/4" seam at the neck, so I want the top of my zipper to line up with my 1/4" seamline. Place 2 pins where the zipper stop should be. Sew the crotch seam with stretch stitch, then where the zipper opens up, change to a regular long basting stitch.
Clip to the seam slightly below the zipper stop. Serge the seam together below the zipper. If you wish, serge the edges of the zipper seam, although in fleece like this, it's not necessary, because it doesn't fray.
Press the seam open. Slide a long clear ruler underneath for ease of pinning.
Pin the zipper in place so it doesn't get stretched out when sewing.
It was a bit tricky to get the top of the zipper to sit straight, so this is what I did with it.
When you start sewing the zipper, move the slider down.
Once you stitch down a couple inches, move it back to the top. Also, slide the pins on the other side back so you don't drive over them.
Pivot at the bottom, giving yourself enough clearance so you don't interfere with the zipper stop. I like to backstitch across this part for reinforcement.
When you get back to the top, move the zipper slider back out of your way.
Continue sewing and backstitch at the end. Remove your basting stitches, and you should be left with a pretty darn perfect zipper!
This is the ribbing for the cuffs. If I wasn't making booties for this onesie, I'd have ribbing at the ankles as well. Same technique for both.
I cut my ribbing by roughly measuring my pattern piece, then using my quilting rulers and rotary cutter to cut them out. Sew it into a tube using a stretch stitch seam. Don't use your serger. This ribbing is crazy and it will not behave in your serger. Trust me. Once sewn, clip a notch into the opposite side for a center mark.
Finger press the seam open. No need to iron this stuff, either.
Fold it into a nice little cuff, and pin it into quarters.
Pin it into your sleeve, adding extra pins inbetween so you end up with 8.
If you have a removeable arm on your sewing machine, now would be a good time to remove it. Fits like a glove. (tee hee! pun intended!) Sew the seam with the stretch stitch.
Turn it the other way up and weasel it into your serger. Goes through pretty smoothly.
This step isn't all that necessary, but it kinda helps to flatten the seam allowance in the right direction. Place the sleeve over a sleeve board or a seam roll, and make sure the ribbing seam is pointing toward the sleeve.
Don't press the ribbing, just the fleece. Again, if you don't want to press your cuffs, it won't make much of a difference. I may even skip this step on my next onesie.
Now for the neck ribbing. This is the only major change I made to the pattern. They just bound the neckline, but I liked the idea of a ribbed neckline like Sue Sylvester's Adidas track suits from Glee, so this is what I came up with.
I chose to make the neckline seam 1/4" because the neckline is huge! The ribbing helps to fill in the hole, but it still has a tendency to droop off your shoulders. I can't imagine what it would be like with just the binding.
I measured the neckline and cut a piece of ribbing 2/3 of that measurement (for sizes L and XL, it works out to about 18") by 4 1/2" wide, folded in half. I marked the ribbing into quarters, and matched the notches up with the center back and the top of the sleeve seams.
To curve the neckline down at center front, keep the seam straight until you get to the front raglan seam, and then turn the ribbing so you end up meeting up with the 1/4" seam at the zipper.
This is what it looks like from the other side. Stitch with the fleece facing up, so you can see the edge, and sew a 1/4" seam with stretch stitch.
Here is what the neckline looks like when finished. As you can see, I also topstitched the seam down with stretch stitching. I also pressed carefully, but if you topstitch it anyways, it's not necessary. Basically, when working with ribbing, pressing is optional. It creases too easily and kinda loses its stretchiness.
I won't go into detail about how I made the booties, but this is what they looked like before I attached them. I think they look like Arthur's elf shoes from The Sword in the Stone.
I sewed 1" elastic around the bottom of the pantleg, and then sewed these on. It took some fitting and measuring to get the length just right. I didn't want the slippers to slide off, so this onesie is pretty much the perfect length. With the ribbed ankle cuffs, you can get away with your pantlegs being a smidge too long, but not with slippers. Accuracy is key here! Another reason why it's easier to do the ribbing instead.
And last but not least, here is the finished onesie!
Here's a close-up of the chest pocket. I just used my 6 1/2" square ruler and hemmed the top edge about 1/2".
The leather bottoms. They look pretty soft and comfy, don't they?
And once again, onesies fit perfectly into the boxes I bought.
Ken was very happy with his Superman onesie. He still told me to keep my eyes peeled for more superhero fleece! I think he wants a whole league!
