Ricardio

Ricardio makes his appearance in his self-titled episode "Ricardio the Heart Guy." The heroes come across him bestowing a Best Friend Massage upon Lumpy Space Princess.

Finn shows a rivalry with him due to the fact that Princess Bubblegum seems somewhat attracted to him, and Finn has a crush on her. This is shown when Finn says to Jake, "I can't compete with that, he's talking about science!" This obviously made him jealous. Finn punches Ricardio in the face once he suspects that he is evil, because he was seen throwing Ice King into a dumpster and carrying rope and broken glass bottles. Ice King then reveals to Finn and Jake that after an experiment had gone awry, his heart left his body, and Ice King began to grow weak. He somehow managed to crawl to the Candy Kingdom and tried to convince Ricardio to return to his body. But instead, Ricardio dumps Ice King into a dumpster, and left him for dead. Ricardio's plan was to cut out Princess Bubblegum's heart and force it to marry him. His idea of the forced marriage was similar to that of the Ice King's usual plans. Ricardio ties up Princess Bubblegum later on in the episode and Finn and Jake save Princess Bubblegum. He is returned to Ice King's body at the end of the episode, and says that he will be back.

Pen has stated that "he'll see you guys later," making it highly possible that he'll return in a future episode.

Appearance
Ricardio is the heart of the Ice King. However, instead of looking like an actual heart, Ricardio's body has the shape of the iconic heart symbol that means "love." Ricardio is fairly small, smaller than that of the small Candy People. He also has a very detailed face (unlike most of the characters seen in the show). He has bold eyebrows, eyes that are depicted as actual human eyes instead of dots, bold nose, wide lips, and cheekbones. Ricardio also possesses arms and legs.

Personality
Ricardio is the heart of the Ice King. Because of this, Ricardio possesses some major traits from the villain. Mainly, Ricardio has an obsession for princesses. Unlike the Ice King however, Ricardio literally wants the hearts of princesses, especially Princess Bubblegum's (as seen in Ricardio the Heart Guy). Some traits that Ricardio possesses that Ice King doesn't is that he's social and charismatic. The Candy People and the Princesses take a liking to Ricardio while they despise the Ice King. Ricardio can also be violent and heartless (ironically): for example, he beats up the Ice King (his host) and throws him into a dumpster. This also proves that Ricardio has no desire to keep Ice King alive by being his heart; he wants a life of his own.

Quotes
See Ricardio/Quotes

Trivia

 * Unlike Ice King, Ricardio is popular and well-liked among the Candy People. Princesses also like him, such as Princess Bubblegum and Lumpy Space Princess.
 * His own name is a pun: Ricardo is "Richard" in Spanish, and Cardio is another word for "Heart" in scientific terms.
 * Even though Ricardio is an actual heart, he doesn't look like one. Instead, he just looks like the "Love" heart design. However, his early designs show him looking like an actual heart, but they probably got rid of this design for it could reveal that Ricardo is a real heart.
 * He is one of the few characters which have many details in the face, while the other, even the main characters, have a "simple" face.
 * Because he's the heart of Ice King, he should be at least as old as him. This was proven in the Adventure Time: My Two Favorite People DVD, on the special feature "Little Did You Know." His species is shown to be a Human Heart, meaning the Ice King could still genetically be a human.
 * Ricardio seems to be too big to be the Ice King's heart, but later in "Ricardio the Heart Guy," he seems normal-sized.
 * Ricardio appeared later on in the series during a commercial on Flicks where Finn and Jake (along with various other characters from The Amazing World of Gumball, Adventure Time, and Regular Show) are in a movie theater, and Jake is annoyed by a beating noise. Later, it is revealed that the beating came from Ricardio, who was sitting next to Jake, watching the movie with a surprised look on his face.