"Greetings! I am Buttercup. I come for those who are in need of help!"
"Golly, it seems to me you're quite confused. Did you come here by mistake?"
"Here, let me help you :) "

I've seen a lot of people doing Swaptale designs and such but not one who changed Asriel's and Chara's place as to who should be the heartless, unfeeling artificial monster and who gets to be a ghost, so here! I bring you Buttercup.

While Flowey tries to be cutesu and defenseless-looking, Buttercup tries to greet the humans who fall in the Underground by looking as much like a human as they possibly can, as to fool them into a false sense of security; Flowey attacks you when you seem like easy prey, but Buttercup knows humans aren't that easy to kill, so instead of taking the first opportunity to murder you, they'll wait, patiently. They'll help you at first, and they'll try to get you on their side and out of everybody else's live, only to end up doing exactly what you thought they would. They're also uncanny, and even if their shape does resemble a human's, it's easy to tell they're not.

The sweater is hollow! Their body is, in fact, as spindly and weak as that of a flower: they've filled their clothes with petals and leaves so that they look fuller and more natural. Their actual leaves are the ones poking out of the sweater's neck!