Hello there! Good job so far! :)) I made a few corrections to your drawing, starting with the proportions. The torso was a little too long, the pelvis was quite elongated, and the feet were too small. After looking at some references of this character at this stage, I noticed that his body is more muscular, so I made the torso wider and gave it a bit more structure, or emphasizing the muscles a bit more, while also emphasizing the muscles in the arms too. Speaking of the arms, the shape of the shoulder and bicep on the stretchy arm looks a little odd. I think it would work better if you first draw the arm and forearm with a clear structure, and then, around halfway down the forearm, start stretching and wrapping it around the character. I also like the idea of having the hand in a closed fist pointing toward the viewer, so that’s how I drew it in my correction. :) Hope this helps!

