A Bever Blister is similiar to a Fever Blister. A Bever Blister is a cold sore that erupts on your lip every so often. Much like a Fever Blister, it is caused by a virus. BUT the Bever Blister originates from a Beaver Virus.
"Franky, remember that Stripper I was dating a few months ago?" "Well, she left me with a little gift. Check out this Bever Blister on my lip!" "Dude, that thing is rude!!!!"