Senku is a scrawny and physically weak young man of average height with pale skin and darkly lined red eyes. He has white hair that fades to green towards the ends, spiking up naturally and resembling a leek. Two locks of hair drape over his face. He has two symmetrical petrification scars on his face, jagged lines beginning from his inner eyebrows and heading towards his hairline. Smaller scars leading down from his inner eye are visible as well. He yaps in-depth about science to teach others