The wolverine face logo was originally from the 1922 and was used again for some merchandise, such as t-shirts and pennants, in the late 80s and early 90s. He has made sort of a comeback in the last few years thanks to Adidas College Vault merchandise. I have several shirts, a hat and a hooded sweatshirt with Biff's face on it. Because the image is rarely used and popular with big U of M fans the stuff is hard to find, most stores that carried the Adidas College Vault clothing sold out. I purchased all of my stuff in Ann Arbor through out the last football season and am glad I did because most of it I haven't seen available since.
I call the old wolverine logo Biff because that was the name of one of the live wolverines from the 1927 season. Michigan doesn't have an actual mascot, they are just called "The Wolverines". They actually use the block M as their logo. During the 1927 season though they had 2 live wolverines from the Detroit Zoo brought to the stadium for big games and they were named Biff and Bennie. They were only used for that one season, and they have never had wolverines in the stadium since. Since then many fans, including myself, refer to wolverines that appear in merchandise as Biff.
Hope everyone had a great weekend & enjoyed the mini Michigan history lesson. Nick