- This monster appears in the artworks of "Snake Whistle", "Goblin Circus" and "Shrub Serpent".
- This card appears in the first Japanese artwork of "Exchange".
- The "Sinister Serpent" seems to be based on the Japanese cryptid, Tsuchinoko, a snake wider in the middle than its head and tail. According to a legend of the Tsuchinoko, it has the power to control minds whereas in other legends it just has the power to lie very very well.
- This card was the first Reptile monster to be Forbidden.
- This is one of several Forbidden cards to go through an errata change to balance them out. The original effect simply returned this card from the Graveyard to the hand for free during the Standby Phase.