|Relatives|| Mrs. Mertens (mother)|
Mr. Mertens (father)
Finn's Baby Brother
|Introduced in|| "King Worm" (dream)|
"The Lich" (actual)
|Latest appearance||"Jake the Dog"|
|Voiced by||Jeremy Shada|
Finn Mertens is Finn from the Farmworld timeline who makes his first appearance in a reflection in the mirror in Finn's dream in "King Worm." He makes his first major appearance in "Finn the Human."
His appearance varies slightly from that of the Finn from Ooo. He has a robotic/mechanical arm fixed with tape, wears a brown sash-like garment (green in "King Worm") which appears to button to his pants. He has longer sleeves, long pants tattered at the ankles, has a backpack identical to normal Finn's but it is sometimes seen as dark green and one solid color. He also has quite a pronounced nose as well as much larger and pointier, slightly more detailed eyes (the eyes and nose also make a slight resemblance to the Earl of Lemongrab or BMO during the dream sequence of BMO Noire) and lacks socks or shoes. His voice is identical to regular Finn, save that Farmworld Finn exhibits a slight "country accent" and a significant lack of the vibrant verbal enthusiasm exhibited by regular Finn.
Finn the Ice PrinceWhen he is possessed by the crown, he undergoes physical and psychological changes similar to those of Simon Petrikov: his eyes turn completely blue (he also gets bags under them) then turns normal for a while when he hears his baby brother cry (which means he is fighting the crown's power and temporarily reclaims his sanity to protect his family, similar to what Simon does with Marceline). His blonde hair appears long and wild (which allows him to fly). He also begins to go insane, only his insanity is quicker, since he allows the crown to take him over, in order to combat first the Destiny Gang, and then the bomb (Simon was an unwilling victim of the crown's power, while Finn deliberately wore it to gain the power of ice). His insanity is evidenced by the deranged monologues he gives about "ice and whispering snow" and about being "the hand of madness," as well as his megalomania and desire to freeze the world. He becomes very protective of the crown when he wears it, urging Jake to "back off my crown [...]! I warn you!" After realizing what has happened to him, he sadly tells his family to go far away on Bartram. It is evident that he doesn't know about the whispers telling him to freeze the world being only to him, as he asks," can't you hear the voices?" to the Destiny gang after he has frozen them.
- The fate of Farmworld Finn and Farmworld Jake is ironic as by the climax, the both of them have become foes to one another and have even become the real Finn and Jake's main enemies: the Ice King and the Lich.
- Farmworld Finn is seen playing a flute that regular Finn had played in the episode "Prisoners of Love." Finn tried to throw it at the Ice King, but he had broken it when picking the lock to the sad ogre's heart.
- Farmworld Finn looks similar to the Mirror Finn in the episode "King Worm." However, Mirror Finn has a strap that matches his bag while Farmworld Finn has a brown strap.
- It's unknown exactly how old Farmworld Finn is, but if he's around Finn's (regular timeline) age, he's presumably 12, 13, or 14 years old.
- Farmworld Finn's mechanical arm appears to be old, as it creaks when it is moved.
- Just as the Ice King uses his beard to fly, Finn uses his long hair to fly with the crown on.
- Both alternate universe Finns have robotic limbs, Pillow world Finn has one same as Farmworld Finn.
- Finn's female past life, Shoko, also has a robotic arm.
- In the Adventure Time Comic Issue #18, Finn goes into an illusion Farmworld area where both he and Jake appear as the Farmworld counterparts. Though he doesn't know anything about it, and is surprised when Jake (just part of the illusion, not actual Jake) cannot speak.
- Although Finn can control his insanity with the crown on, he is able to do so without taking it off, in opposition to Simon Petrikov.