|“||Now I'm going to cut out Princess Bubblegum's heart and make out with it!||„|
Ricardio is a reacurring antagonist in Adventure Time. Her serves as the main antagonist of the Season 1 episode “Ricardio the Heart Guy”, the Season 4 episode “Lady and Pebbles” and a major antagonist in Season 9.
"Ricardio" is a combination of Richard and cardio a Greek word for heart. Ricardio is an actual heart (Ice King's heart) that the Ice King accidentally brought to life. He wanted to seduce Princess Bubblegum with science so he could rip out her heart and make it his wife. He is defeated by Finn and Jake, and Ice King puts him back in his chest, with Ricardio vowing vengeance.
Three seasons later, he returns again, escaping from Ice King's body and using Ice King's internal parts to build a larger body for himself. This time, he defeats Finn and Jake by poisoning them with Zanoits (the subject he was discussing with Princess Bubblegum in his first appearance). He explains that he was thinking too small last time, and now wants to marry Princess Bubblegum entirely, not just her heart. She challenges him to hand-to-hand combat that if he won, she would marry him. She quickly hit the exposed tendons of his newly built "body" and defeated him, telling him to get out of her sight. Princess Bubblegum later builds Ice King a new heart, which means Ricardio is still a separate entity.
- He is voiced by the Star Trek veteran actor George Takei.