Within moments of his reveal, Reiji Akaba has been christened by many as "Hipster Kaiba", especially when he wears that trendy hoodie while eavesdropping in episode 9. Just take one look at him and no further explanation is needed.
Yuya has been nicknamed "Tomato Head" by many. Once again, such a name needs no explanation.
Yuya being sad, uncomfortable or upset. Wilting/rotting tomato.
The Dark Duelist is also referred to as the Goth Duelist or Edgeplant.