The Cleveland Browns were originally named after their owner, whose last name was...you guessed it, Brown.
(From my memory, so it might be a little off but I believe the general idea is correct) Sooner was a term from way, way, way back in the 1800's. I'm a little shady on the exacts, but when the United States was "expanding" people could claim the land in these new states (like Oklahoma). The people were supposed to wait so everyone would have a fair chance of getting the land they wanted, however some people cheated and went ahead sooner than everyone else, giving them the name, Sooners.
Crimson Tide is a great movie staring Denzel Washington and Gene Hackman.
Oh, THAT Crimson Tide.
"In early newspaper accounts of Alabama football, the team was simply listed as the "varsity" or the "Crimson White" after the school colors.
The first nickname to become popular and used by headline writers was the "Thin Red Line." The nickname was used until 1906.
The name "Crimson Tide" is supposed to have first been used by Hugh Roberts, former sports editor of the Birmingham Age-Herald. He used "Crimson Tide" in describing an Alabama-Auburn game played in Birmingham in 1907, the last football contest between the two schools until 1948 when the series was resumed. The game was played in a sea of mud and Auburn was a heavy favorite to win.
But, evidently, the "Thin Red Line" played a great game in the red mud and held Auburn to a 6-6 tie, thus gaining the name "Crimson Tide." Zipp Newman, former sports editor of the Birmingham News, probably popularized the name more than any other writer." -
http://www.rolltidefan.net/tradition.htm