- This card's Number comes from its owner, Quattro, whose name is the Roman numeral for 4.
- This is the second "Gimmick Puppet" "Number". The first is "Number 15: Gimmick Puppet Giant Grinder".
- This card resembles "Number 15: Gimmick Puppet Giant Grinder" in a certain way: Both reveal themselves having hollow chests without hearts in them. "Number 15" has grinders instead, and "Number 40" has strings in the left part of his chest where its heart should be.
- As with most other Xyz Monsters with them, when this monster absorbs an Overlay Unit, it absorbs it through its sword.
- When this monster activates its effect, it plays the strings on its chest with its sword like a harp, then red, glowing puppet strings come down from a portal and attach themselves to every other monster on the field.
- This is the first "Number" monster where the "Number" printed during its Summoning in the anime and the Number on its body are not the same color. When it is printed during its Summon, the Number is a plum color, but on the monster itself, the Number is red. This might be an animation error.
- This is the second "Number" monster that requires a specific Attribute for its Xyz Summon. The first is "Number 96: Dark Mist", though in both cases, this only applies to the anime versions.
- This card, like "Number 15: Gimmick Puppet Giant Grinder" and "Number 33: Chronomaly Machu Mech", are the first Numbers seen to not be obtained either by Astral or Kite even after their owners have been properly defeated in a Duel.
- The number 40 can be seen on the top of this monster's wing.
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