Flowey is the Incarnation of Despair.
Flowey has a small green root big yellow petals and a white core black simple eye's and mouth when creepy black around the core a withe dot eye's.
Despite his first appearance, he is no innocent happy go lucky flower. He dangerously loves to manipulate people and trick people either to complete his schemes to get them in a position to kill his victims he is very croaked and loves to see others suffer. He wants to become a complete god so he can control and make many suffer.
He was born as the Incarnation of Despair from the blood of Chara and the dust of Asriel, the god of hope. After that, he follow the corrupted Chara who allowed him, as long as he doesn't stay to close.