Never was into tattoos, so looking like a tattoo fan sounds like one idea for Halloween, if the temporary ones are easy to take off for the next day. Or, does it get into the clothes?
I have seen a wide variety of the wet and press on tattoos it takes a little practise but they can look like real tattoos. I am sure different brands work differently. Henna tattoos stay on for awhile longer whereas the wet and press on stay on until they are worn off or taken off with alcohol and some rubbing. Be careful where you put them if you want to remove them because they take a little effort to remove and a sensitive area is unpleasant to remove it from. I use to do plenty on the kids. The glitter rhinestone ones often do not usually stay on very good and may require a better glue than they come with. I am sure one can use the super glue to attach these better to the skin but it will take awhile for them to come off because the skin will have to be shed or pulled off with it. What determines how a tatoo affects the skin and how long it stays is how it is applied and what it is made of. The plastic wet and press ones do not tend to have colors come off on clothing. I am sure they have information on the internet about tatoos. I knew a beautiful Asian woman who use to come in with these incredible wet and press on tatoos over her very nice chest that looked real but as every few weeks they would change it was obvious they were temporary. The wet and press ones I put on the kids stay on pretty good for about a week then begin wearing off but to get them off faster for school their mother takes alcohol and rubs enough that the kid got tired of the tatoos and no longer want them unless they are on the shoulder where they can be hidden by a sleeve.
I would suggest you practise awhile before Halloween as to applying the temporary tattoos so that you can do a good job on Halloween. Often the dollar stores have lots of smaller ones and various sizes to practise with. Just put them where you can cover them or easily remove them. Start out small and build up. The ones I buy come in sheets and I cut out what I want to put on. Once you begin to apply it is difficult to fix them so begin with some inexpensive ones for practising if you intend to go on to the really nice bigger ones that can be purchased at various places and probably on the internet.