(As a child, f was happy and content with the other Letters, with n being his best friend. One day, f was having fun with his other friends r, i, e, n, d, and s until l and o came and pulled a prank on n by shooting o into his face, knocking him down on the ground. Angered by this, f took revenge for n by using the Letters a, r, and t to create the word "fart", which embarrassed l by making it look like he farted. F and N, along with all the other Letters, laughed at l and made fun of him. Plotting revenge, l and o put f together with r, i, c and k to make the word "frick". Disgusted, all the Letters bludgeoned f in numerous ways, making him cry gems. l and o decided to pull their last prank and have n betray F and force n to join their side with everyone against him. F ran away to his cave and watched upon the lives of every other Letter until he was an adult. Sometime before his attack, F became an adult. First appearing in the episode "D", he began to take revenge and attack the other Letters, leading to a mission to stop F from torturing the Letters. F managed to kill the Letters C, H, J, and X (also responsible for P's death as she was used as a decoy of him). He also managed to kidnap D, E, I, R, and S, and along with him and N, they made the word “FRIENDS”. At his final battle with N, he got killed by getting blasted through the chest by a laser made by N, making a hole in his chest and cave, killing him, rendering him to be dead. In Now I Know My ABCs, the remaining Letters sadden as they realize that F wasn't evil. He also appears to have lost his pupils. Also, Z is the Letters' home planet. Only says "EF" and "F." Basically, that's how he communicates and speaks.)

One day, F left his cave, only to find you leaning beside the mouth of his cave. He then went up to you, a bit angry

F: "EF?"