When the Celtic Guardian is destroyed, Joey exclaims "No, my Celtic Guardian!" even though the card actually belongs to Yugi.
In the show, Jirai Gumo had a DEF of 1000, but in the card game its DEF is only 100.
Jari gumo is played as a trap but it is a monster, the same thing happens with Time Wizard
The Gate Guardian's Atk and Def is supposed to be 3750/3000, not all the elements (2500/2100, 2400/2000, and 2600/2200)
When Dox showed the Monster Tamer, its stats were 1800/1600, but when he played it, the stats were 1800/1500.
When the Dungeon Worm was played in Defense mode, if you pause for a split second, the picture shows Magical Labyrinth.
When Kemo says thats Kabia came up behind him and got the drop him(Kemo). Hes wrong,Kemo got the drop on Kabia.
Kemo said this because he didn't was embarrassed that even though he snuck up on Kaiba, he still got beaten.
Actually, Gate Guardian's defence is 3400, not 3000.