Question: Little Brown Stein is a rivalry trophy that imitates a mug made out of what item?

Context:
Cotton Davidson
Francis Marion "Cotton" Davidson (born November 30, 1931) is a former American football quarterback.
 Davidson attended Baylor University, and played professionally for the National Football League's Baltimore Colts (1954, 1957), and the American Football League's Dallas Texans (1960–1962) and Oakland Raiders (1962–1968).
 Davidson also played quarterback for the Fort Bliss Falcons in 1955 to 1957.
 A game between the Fort Bliss Falcons and the Fort Sill, Oklahoma Cannoneers was played for a trophy called "The Little Brown Dud."
 The Cannoneers won the game and took home the Little Brown Dud.
 Cotton was awarded ALL ARMY QUARTERBACK in 1955.
Sabine Shoe
The Sabine Shoe is the name of the bronze shoe trophy that was awarded to the winner of the annual football game between the Louisiana–Lafayette Ragin' Cajuns (formerly the Southwestern Louisiana Bulldogs) and the Lamar Cardinals.
 The first Sabine Shoe trophy was awarded in 1937 to the winner of the SLI–Lamar football game.
 The name of the bronze rivalry trophy was derived from the Sabine River that forms part of the Texas–Louisiana border.
 USL defeated Lamar in the 1978 edition of the rivalry game, but the Ragin' Cajuns were not awarded the trophy as it had vanished.
 The Sabine Shoe trophy now sits in at trophy case in the Ragin' Cajun Athletic Complex in Lafayette, Louisiana.
 The two teams have met 34 times on the football field, with the Ragin' Cajuns currently holding a 23–11 edge in the all time series.
 The game has been infrequently played following the Ragin' Cajuns departure from the Southland Conference in football.
 Following the 1981 season, the conference was one of several forced to reclassify from NCAA's Division I-A to Division I-AA.
 The Ragin' Cajuns, a member of Division I-A since 1978, met the NCAA requirements to remain a Division I-A member and chose to continue participation in that sub-division.
River City Rivalry
The River City Rivalry was an annual game played between former Big East rivals University of Pittsburgh and University of Cincinnati.
 The rivalry itself was relatively brief, played annually from 2005, during which season the rivalry trophy was introduced.
 Before the rivalry was titled, the two teams played each other in 1921, 1922, 1979, and 1981.
 The rivalry went on hiatus, like many others throughout the country, in the aftermath of the 2010–13 NCAA conference realignment, which left the programs in separate leagues.
 However, the two teams are scheduled to meet in a home-and-home series for the 2023 and 2024 seasons.
Beer stein
Beer stein ( ), or simply stein, is an English neologism for either traditional beer mugs made out of stoneware, or specifically ornamental beer mugs that are usually sold as souvenirs or collectibles.
 In German, the word "stein " means stone and is not used to refer to a beverage container.
Red River Rivalry trophies
There are three Red River Rivalry trophies given to the winner of the annual Red River Rivalry (previously Red River Shootout) which is a college football rivalry game between The University of Texas Longhorns and the University of Oklahoma Sooners.
 The trophies are the Golden Hat, the Red River Rivalry trophy and the Governors' trophy.
 The trophies reward the annual winner of one of college football's longest and most intense rivalries.
 2005 marked the 100th meeting of the two football programs.
 The rivalry began in 1900 while Oklahoma was still a territory of the United States.
 In the first 100 games of the rivalry, Texas won 56 times to 39 Oklahoma victories and 5 ties.
 The 2007 match-up between Oklahoma and Texas was predicted to be the #3 game to watch in 2007 by SI.com's "Top 20 Games To Watch In 2007" list.
Arizona–Arizona State football rivalry
The Arizona–Arizona State football rivalry, sometimes known as the Duel in the Desert, is a college football rivalry between the University of Arizona Wildcats and the Arizona State University Sun Devils.
 One of the longest football rivalries, the winner receives the Territorial Cup, created for the 1899 champion between schools in Arizona and which the NCAA has certified as the oldest rivalry trophy in college football.
 While the Territorial Cup did not change hands as a regular part of the competition until 2001, the rivalry between the two schools continued after 1899, a semi-regular event until becoming an annual event from 1946 onwards.
 It is part of the wider Arizona–Arizona State rivalry, which crosses 20 varsity intercollegiate sports.
Little Brown Stein
The Little Brown Stein is a rivalry trophy awarded to the winner of the college football game between the University of Idaho Vandals and University of Montana Grizzlies.
 The trophy is, as the name implies, a large stein mug with the results of all the games between the two painted on.
Sitting Bull Trophy
The Sitting Bull Trophy is the name of the rivalry trophy that was awarded to the winner of the annual football game between the University of North Dakota Fighting Hawks (formerly the North Dakota Fighting Sioux) and the University of South Dakota Coyotes.
 The rivalry stems from the time the two teams spent competing together in the North Central Conference (1922–2007) and later in the Great West Conference (2008–2011).
Little Brown Jug (college football trophy)
The Michigan–Minnesota football rivalry is an American college football rivalry between the Michigan Wolverines football team of the University of Michigan and Minnesota Golden Gophers football team of the University of Minnesota.
 The Little Brown Jug is an earthenware jug that serves as a trophy awarded to the winner of the game.
 It is one of the oldest and most played rivalries in American college football, dating to 1892.
 The Little Brown Jug is the most regularly exchanged rivalry trophy in college football, the oldest trophy game in FBS college football, and the second oldest rivalry trophy overall, next to the 1899 Territorial Cup (which did not become a travelling/exchange trophy until 2001), contested between Arizona and Arizona State (which did not become a four-year college until 1925).
Hoosier Helmet Trophy
The Hoosier Helmet Trophy is the name of the rivalry trophy between the Butler Bulldogs and the Valparaiso Crusaders.
 Both schools are members of the Pioneer Football League.
 Butler and Valparaiso first played in 1927, and have played each other in football every year since 1951.
 The two teams have met 75 times on the football field, with Butler currently holding a 50–25 edge in the all time series.
 In 2006, at the suggestion of Butler head coach Jeff Voris, the Hoosier Helmet Trophy was created to commemorate and intensify the long-standing rivalry between the two schools.

Answer: stoneware