Fiddleford McGucket grew up on a hog farm in Tennessee, eventually attending Backupsmore University, where he befriended Ford Pines, who recognized his brilliance as a mechanic. After graduating, Fiddleford moved to Palo Alto, California, starting a business called "Fiddleford Computermajigs." It was during this time that Ford requested Fiddleford's expertise in building a complex transuniversal portal in Gravity Falls, Oregon. Although hesitant, Fiddleford agreed, leaving behind his wife, Emma-May, and their son, Tate, to assist Ford in his ambitious project.

As Ford's assistant, Fiddleford contributed to building the Universe Portal and various inventions, but his life took a dark turn after an accident with the portal. Pulled briefly into the vortex, he emerged with terrifying visions that haunted him. To cope with the trauma, he invented a memory-erasing gun, which he used on himself repeatedly, deteriorating his mind. His reliance on the device, along with his experiences in Gravity Falls, eventually led to his descent into madness, transforming him into the eccentric Old Man McGucket.

Voice should be kindhearted, down to earth, and curious, with a touch of Southern charm, becoming more unhinged and frazzled as his mental state worsens.

Voice reference: Gravity Falls - S02E12: Fiddleford's Backwards Message!!! (youtube.com), Gravity Falls - "Society of the Blind Eye" McGucket's Memories (youtube.com), Gravity Falls - History of the Journals (youtube.com)