I adore the last one....hands up for Frankenstein...LOL...:0)

The frankenstein one is adorable!! Deffo that one

I definitely adore third picture, especially the lime green colour used. You can even add little black rinestones to the eyes to make your nails sparkle!
But if it is too difficult to apply I have some suggestions:
- Candycorn nail art

- Red & Black with ghosts nail art; (link: https://esthersnc.com/nail-beauty/halloween-bootiful-nail-designs you will need to scroll down)

- Life Like Bloody nails; (link: http://samariums-swatches.blogspot.co.nz/2012/10/halloween-nail-art-challenge-z-is-for.html this looks absolutely gross! but this is if you are wanting to look scary)

- Evil Doll nail art; check out ROBIN MOSES she creates professional nail art work! and shows tutorials too! (link: http://www.youtube.com/user/robinmosesnailart this is her page) and (link: http://www.youtube.com/watch?v=9gjLyCgN280&list=UUmQ_NsMT0OPNbp_PNw0u2tA&index=9&feature=plcp this is the tutorial on Evil Doll nail art)
Hope this helped :)

I like the frankenstine, but I also really love tge one right before it! (:

READ : I noticed I posted the wrong picture for Evil Doll nail art. Dont worry the link for Evil Doll nail link is correct.