how do i add a fixed image to the corner of my screen?

i hope that makes sense currently, theres the slenderman on my profile, but its not fixed just above the taskbar while you scroll. THIS IS SO HARD TO EXPLAIN HELP 

is it an issue with the other codes im using causing this one to not work? or is it an issue with the code itself? currently im using this one 

<!-- (c) Layout created by ꒦꒷ 𝖘𝖔𝖕𝖍𝖎𝖊 𖦹 ⋆｡✩ (https://layouts.spacehey.com/layout?id=103431) -->

<div style="float:  ; max-height: 300px; position: fixed; left: -680px; bottom: 1250px; z-index: 200;">

<img src="https://64.media.tumblr.com/a1a315762b587e7ad2ab29e72fc4ba11/454e2fc8a2e25778-7a/s640x960/86e8c48307ab74c48dadb38718963003dfaee899.pnj" height="300"/></div>

i changed the position so itd show when you go onto my profile, any tips/suggestions on why its not working as its supposed to? :/

EDIT: ive noticed its likely because of the bouncing effect on the profile, where everything is moving up and down. ive looked around and only people with that same effect have the same issue as me. is there a way to fix it???????