Oakland A's (MLB, Alternate Logo, 1994)
The Oakland A's elephant logo is a timeless classic that dates back to 1905 and the teams nickname as the "White Elephants". In 1994, the A's decided it would be a good idea to add a pair of shades to their majestic mascot. Terrible, horrible, god awful idea. The logo was scrapped after just one year of use, with the sunglasses removed, all order was restored.
New York Islanders (NHL, Primary Logo, 1995-97)
Did the Islanders pull in some sort of sponsorship deal with Long John Silvers in order to go with this monstrosity? That is the only reason why one of the dudes from Deadliest Catch should be in goal on your logo.
Baltimore Orioles (MLB, Alternate Logo, 1965-67)
In the 1960's, LSD became a very popular drug amongst Ken Kesey, his Merry Pranksters and just about everyone else. The drug also seemed to be very popular among mascots in Baltimore, as this Oriole appears to be going on his 23rd or 24th straight Grateful Dead show.
Sacramento St. Hornets (College, Primary Logo, 1991-2003)
The fact that this logo managed to survive at Sac State for 12 years just simply blows my mind. It looks like something a 10 year old put together on Microsoft Paint. Also, why does the Hornet not have eye balls?
Harlequins RL (Rugby Super League, Primary Logo, 2006-Present)
Harlequins has always been a middling club since joining the RSL and their teams logo certainly isn't helping things. Nothing strikes fear in to the heart of your opponents more than a court jester attempting what appears to be a plié.