They are very hard to find in my experience, but I think if more people knew what to look for, it might be more common than people realize
As such, if playing huge creatures and trampling over everything appeals to you, my best advice is to play [c]Gruul[/c]
Psychic Nightmare X WIND Level 6 [ Psychic / SynchroEffect ] ATK 2400 DEF 1800 1 Tuner + 1 or more non-Tuner Psychic-Type monsters Once per turn, during your Main Phase, you can pick 1 random card in your opponent's hand and call what type of card it is (Monster, Spell or Trap)
This might be due to a card customisation system, which allows players to unlock skills that can boost stats, give them summon abilities and other modifiers
Try a quick lookup in your browser using PokeScopes free value tool
This isnt to say each set had dozens of these cards