A large glass jar. Any jar should do. I chose one I can close up to actively manage the humidity.
There are certainly better blends than others and you can increase the happiness of your plants by using the correct mix. I just grabbed some basic potting soil.
Again, this was a bad idea. Please see my carnivorous plant potting soil Instructable
for a mix that won't kill your plants.
The plants. I went with a classic Venus Flytrap
and an interesting Sundew
. Probably could have used at least one more but I'm hoping they'll grow to fill in the spaces and I'm trying to encourage some moss as well. There's always time to add more if it looks too sparse.
Animal skull. I used a raccoon skull I picked up at the same shop I got my plants from but I have a growing collection of type specimens I've been collecting since childhood and then used extensively working as an archeologist. Best to not use something unusual. A raccoon was the perfect size and you can get them cheap on the internet if you can't otherwise obtain one.
Distilled water. Tap water or even bottled water will kill Venus Fly Traps and other bog plants. I'm told rainwater is OK as well and has been good for my orchids but I haven't tried it on this type of plant. Distilled water is inexpensive so there's no reason not to use it. Bottled drinking water often has salt added for flavor and will kill your plants and while chlorine is very bad for them it's not the only thing in tap water that will kill CP's. So setting it out over night won't help in this case.
Total cost if you go out and buy everything is probably around $40.