Lenny is a lovable goof who pesters Laverne and Shirley, along with his best friend and roommate Andrew "Squiggy" Squigmann, both of whom live upstairs from Laverne and Shirley's lower-level apartment. Lenny works as a truck driver at the Shotz brewery. Lenny says that, while he is not completely sure, he thinks his last name (Kosnowski) is Polish for "Help, there's a hog in my kitchen".
He had a rough childhood when his mother abandoned him on his 5th birthday. Lenny is Polish and is 89th in line for the Polish throne. In school, Lenny befriended his lifelong best friend, Andrew Squigmond, or Squiggy, as we all know him. He also grew up with Laverne, Shirley, and Carmine Ragusa.
Lenny & Squiggy secured jobs as truck drivers for Shotz Brewery. Lenny lived with his brother-in-law until Squiggy needed a roommate and the guys moved into the apartment building, also occupied by friends Laverne and Shirley. Lenny and Squiggy also had a musical group going called, "Lenny & the Squigtones" where they sang a memorable song, "Night after Night." When friends Laverne & Shirley needed transportation to California, Lenny & Squiggy drove them cross-country.
They liked California so much, they decided to stay where they opened their own talent agency called, "Squignowski Talent Agency." Lenny always dated several women, although it seemed his heart always belonged to his best girl friend, Laverne. Afterall, he was "The Lone Wolf." But in the end, when it came to Lenny & Squiggy, they were always hilarious and best pals.