You can’t put stickers on a cat.
Okay, technically, you can, but you shouldn’t, not even when it would be super helpful to keep track of over a hundred cats (QR codes, anybody?).
They certainly don’t need any additional decoration. They certainly would not benefit from a coating of Lisa Frank collectible stickers. The adhesives would make a great big mess of their fur.
Cats need zero help with making a mess of their fur.
Just as there are people with uncombable hair, there are cats with apparently uncombable fur (okay, it can be combed, but it will never look that way).
This is neither a matter of matting nor of fighting (like Anka) for the right not to be combed. But, that’s not truly a mess, even though it can look messy. Making a mess of fur doesn’t even have to do with whoever chooses to stick their head in water fountains. Wet and mess aren’t exactly the same sort of thing, either.
Some of the messes, aside from their tresses, are those that cats make of their faces. Chiefly, this is due to enthusiastic eating. Witness Tucker. Tucker is a tackler. For evidence, we call Oram to 
the bench. Oram is also a tackler, but mostly sticks to tackling Tucker back (maybe that’s forth…it’s hard to keep track of their shenanigans). Tucker, on the other hand, tends to tackle treats and fish mush with extra gusto. It’s this type of tackling that gets Tucker’s nose messy and can cause brief, albeit easily eased, concerns when viewed from a distance.
There are other cats who make messes of their spaces rather than of their faces. Mostly, this has to do with mealtimes, gravity, and, again, enthusiasm. Luscious lounge lady Lynette has superior amounts of zeal to spare. She also has an amply furry face, all the better to collect tidbits of dinner…and breakfast, and elevenses, and brunch, and lunch…for revisiting at leisure, whenever she decides it’s time for a bath or snacks.
Even Carrot has occasionally been spotted with a wee bit of something edible marring the perfection of his white and orange coat. Mostly careful to groom himself to a gleam, the tendency 
toward messiness is part of a cat’s milieu. Maybe that’s why they so often groom each other so energetically. Surprise treats! (Um…eeeeew.)
Grooming is another reason you can’t put stickers on a cat. Worse than fur, adethives can geth thtuck on thtongues and make more thtuff more methy, noth thto menthion sthwallowing thtuff they sthouldn’t. Ahem… adhesives can get stuck on tongues and make stuff more messy, not to mention swallowing stuff they shouldn’t.
With all of this in mind, maybe we should say, “you shan’t put stickers on a cat.” Sure, it can be done, but just because something can be done doesn’t mean it should be done. With cats it’s better to stick with loving linguistic labels. Leave the stickers for groceries and laptop decorations.