Vicious Russian hooligans at Euro train and prepare to fight (The Associated Press)

Don't be fooled by the wacky names like ''Music Hall,'' ''Happy Guys'' or ''Aliens'', highly-trained Russian hooligan groups are as nasty as they come and tune up for ultra-violence on a regular diet of pre-arranged fights throughout their domestic season and - whenever they can - in Europe. Viciousness and organization are the hallmarks of these ''firms'', who have put aside their domestic rivalries at the European Championship. With the exception of Polish hooligans, they are the most consistently violent around.