Stimulus Monsters are monsters created by LHK. They are stored in the Extra Deck, and for their Summon, they require monsters on the field for the Summon written in its Materials, when an action is done. Notable is that this Special Summon occurs at Spell Speed 2. They also have negative Levels. They have three colors in its border, with green in its top, blue in the middle and red in the bottom.
- Gestalt Psychosis Stimulus Dragon
2 Level 4 or lower EARTH monsters with a positive Level - when your opponent activates the effect of a monster Special Summoned from the Extra Deck
How it works: Say your opponent uses Scrap Dragon's effect to destroy one of his cards and 1 of your card, while you control Zoodiac Whiptail and Zoodiac Thoroughblade. Since Scrap Dragon was Special Summoned from the Extra Deck and activates its effect, you can use said Whiptail and Thoroughblade and send them to the GY to Stimulus Summon Gestalt Psychosis Stimulus Dragon.