He has much of the same appearance. Black underwear, a green belt. Red boots, and to top it off, spiky hair.
an image of him is to your right.
This robot is much more curious. He has no memories of Tobio. He is much more childlike.
When Doctor Boyntons son, Toby dies in a car accident when he feels unloved, he tells Doctor Boynton to treat the new robot as he would his son. After this, they go on a cruise where Boynton lashes out at Astro for misbehaving. He signs himself away to the robot circuise, but is freed by faking his death. This is when Doctor Elephant takes the newly named Astro Boy in, and builds parents for him.
He has a little sister, his robotic parents, Doctor Elephant and Doctor Boynton.