Terrarium Animals

I want to make a mini terrarium that animal could call home. Is this possible. I want something small and cheap. How can I do something like that? What am I? What kind of animals could live inside?

Well, you should do more research. Your public library probably has a book or two to lend you. In addition, it is interesting? If you love frogs, this is different from that which has a lizard or small snake and different from that of butterflies and insects. So, you have decisions to make. Also, you must decide how much time and effort you put into it. A frog or salamander should water changes and greater attention than it might have some bugs in it.
When you say mini - What size do you think? I have seen very little, but personally I'd go with a 10 gallon aquarium. You can get them cheap at garage sales or friends, especially if they leak too much for fish. A leak will be excellent work for a terrarium, just put a liner such as plastic down if it leaks right on the merits. Then a layer of activated charcoal, you can get at any pet supply or discount store that sells fish supplies. Then cover with a layer of earth or pebbles aquarium. The last I did, I kept most of the plants in pots small and medium-sized and not fill the aquarium with soil, just pretty rocks, and vines were lying everywhere. I always put charcoal in it because it keeps it fresh instead of letting sour. I used some artificial plants too far back and fill bare spots and a plastic rabbit had a look on the back corner. It was cute, although I can not say so. It had a fountain that I borrowed from a friend, then I had a problem hiding the rope, so I used a vine to do artificial. If I added a small pond instead of the fountain, I would put him in a shallow glass bowl and piled up rocks to make a beach "around it. (Pebbles and stones a few more too .)
Raising butterflies is not so difficult, but the larvae feed on plants, so they should be replaced. After watching for a day or two, release the butterflies so they can go and multiply. Do your research and know what they need to eat. For water for worms or bugs, you just define a cotton ball on a plastic lid, and damp. Replace if it goes wrong. I think the crickets are kind of interesting, or pet store and sells exotic bugs like spiders or tarantulas giant hissing cockroaches - yuck! But maybe something interesting.
Get more information on frogs, snakes, lizards, bugs and so you can be sure to take good care of them.
If you make your terrarium with local life, you can release them if necessary, or take more. Just do not let your terrarium be a death camp, if it takes too much care or you get busy and can not do it just get plastic animals, OK? Also, do not put too much there, it's better with less.
Let me see, what do I forget? If she smokes up really bad, then open and the fresh air for some time. If it dries too quickly, cover the openings with plastic wrap. It is difficult to get the perfect balance in order to check every day or two to see if water needs added or it is too wet.
Maybe that sounds like too much work. It does need some care, a little here and there, maybe 5 minutes and one hour 1 / 2 times a week to clean, pull the dead leaves and pinch the plants that grow too large. Depends on what you have in him. They sometimes advertise that they need no care at all, but I do not think so, not long term and happy and clean. He must have some attention.
Living well and doing good. Good luck.
I forgot to mention the fish, very small or a goldfish or Siamese fighting fish in a bowl inside the terrarium. I'll try that myself sometimes!
What about tadpoles?