IS there a specific name for these types of dolls? I'm assuming they're the same as I've seen before, where you nail them to a tree or something, probably to curse the person in mind. Are they just voodoo dolls or are they different?

They're usually made of a few bundles of straw, and are called 藁人形 (waraningyou). You may have heard this word in the intro to 魔理沙は大変なものを盗んでいきました (post #92943), for example.