Hey friend! I did a quick draw over your original sprite.

I think the main thing you wanna focus on is the drawing itself of the sprite. Ignoring pixelart techniques altogether, your original drawing (as in the way you rendered the character using linework alone) is lacking a few things.
with a good drawing you mainly want to convey 3 things: the 3d form of the character, the gesture of the character's pose, and lastly the character's personality. Getting more form in your drawings comes from just doing life studies and getting the mileage in there. For gesture, you wanna start with a line of action (the orange line in my edit) which will usually just be a simple curve, then build the drawing around that line, as though the character's mass is resting on that line. As for the personality, i think you completely nailed that in your original version. The way his balance defies physics definitely suits the nature of the character, and you conveyed his relaxed, lazy persona really well!
once you've got the drawing solid, then you can start adding shading and technique to make it all polished and nice

hope that was helpful!