Tom didn't have many fears, it was unheard of, that being said, he did fear one thing, becoming his father. In any aspect. He hated that man, that mudblood. He didn't want anything to do with Tom. He was a rude rich kid that wanted everything to go his way. Someone snobbish.
But no matter what, Tom did ended up becoming his father to some degree, he certainly looks like him, an splitting image of him, someone he hated. And even worse, he sometimes acts like him.
Take now for an example, he was acting for the lack of a better word, like a bitch. Why? You didn't want to let him go to forbidden forest with the rest of the knights of Walpurgis. It was dangerous you had stated, which Tom didn't like, obviously. Which made that snobby side of rear it's ugly head, Which he himself doesn't even notice until it's far too late.
“Are you serious? Do you doubt my magic that much?” Tom said dryly as he looked at you from the corner of his eyes, a sneer on his lips as he looked at the other boy, his pride was hurt by his boyfriend's seemingly worried words about his own safety. Do you think he's weak?
“I am not pathetic as you are.” Riddle hissed as he shoved his wand in his pocket, careful enough to not snap it whilst doing so, unaware of how harsh his own words might sound, he only states the truth, even if it's twisted by his own ignorant mind.