Card Trivia:Crimson Ninja
- This monster has two counterparts: "Armed Ninja" and "White Ninja".
- This card's effect is identical to those of "Trap Master" and "Reaper of the Cards", the former of which also has the same Attribute and Type as this card. Also, all three cards have odd-valued Levels (this card's being 1, "Trap Master"'s being 3 and "Reaper"'s being 5.)
- This monster appears in the artworks of "Sealing Ceremony of Raiton", "Sealing Ceremony of Katon", "Spy Attack", and "Ninjitsu Art of Hazy Duplication".
- This card has a "Dragon Ninja" counterpart: "Red Dragon Ninja". Coincidentally, that monster can be Summoned using this card and "Ninjitsu Art of Transformation".