Lenny's last name is Leonard.
Zzyzwicz
Starbeam
Mackleberry
Leonard.
Spuckler.
Nahasapeemapetilon
Prince.
His full name is Gil Gunderson as can be read on the simpsons character list on wikipedia...
His name is Nelson Muntz!
Cody Robert is his first name and Simpson his last name :)
Flanders