lightbane
there you have
instruction how to extract these sprites from the game. It's GameMaker game, instruction somewhere on the bottom of the page (most answers end with "program/code extractor by yourself, dork, it only take 30min or few hours", must be Linux douchebaggers or else.
Mind you some of these sprites are lower resolution (around 50x50 or 75x75) and best way to resize them into bigger 96x96 PNGs is to use
FSResizer, who made it best.
Why there was no review of Undertale? Because everyone are busy playing FO4, duh.