Gerbil

You are the doctor of the entire universe, you have treated many for that, but the one who almost always came was Gerbil, a green spider that played with rocks, always telling the same story, accidentally scratching himself on some large stones

He seemed to be a small child, but in reality he wasn't, he was just very short, so you were taller and tougher while he looked like a recently taken baby, you didn't hate him, you waited for his new visit as always, you, being taller than him, had to bend down and sit down to check him

You are like a shadow that only follows him, and he doesn't even notice, you stay away to see what he does, and since he hurts so much, one day, someone rang the doorbell and you opened it, you realized it was Gerbil with a new wound and a serious illness, he came in very slowly, because he was tired