Rocky and Mugsy
Rocky first appeared in the 1946 film Racketeer Rabbit where Bugs decides to find himself a new home, but the one he chooses is unfortunately occupied by a duo of bank robbers. The characters here are called "Rocky" (drawn like movie gangster Edward G. Robinson) and "Hugo" (a caricatured Peter Lorre).He later appeared in Golden Yeggs as a criminal who wanted Daffy Duck because he thought he could apparently lay golden eggs which were actually Catty Cornered where they kidnapped Tweety because he was worth a lot of money, Sylvester unknowingly rescued him after attempting to eat him many times and he was greatly rewarded.
Rocky next appeared this time with Mugsy in his first appearance in Bugs and Thugs where they unknowingly kidnapped Bugs Bunny after robbing a bank they concluded that he knew too much and held him hostage. Bugs attempted to call for help at a gas station but they saw through him and yanked him away from the phone, later on he tricks them into getting hit by a train which they survive afterwards, they force him to rebuilt their car and drag the car to their hideout. Once there Rocky orders Mugsy to kill Bugs by saying "You know what to do, let him have it!" while entering the room he points his gun at Bugs and Bugs says "You heard him let me have it" and he stupidly gives him the gun and he shoots Mugsy in the face and he stumbles next to Rocky and says "Duh, I let him have it boss, just like you said" he then faints and lands on top of Rocky and he punches him off. Next Bugs makes a siren sound and pretends to be a cop by using a thick Irish accent and he tells them to hide in a stove he goes into a conversation with himself pretending to be a cop he says "Where's Rocky?, where is he hiding?", "He's not in the stove!", "Ho Ho he's hiding in the stove eh?", "Look pal if my friend Rocky was in there would I toin on the gas and toss a lit match inside?", "You might rabbit, you might", "I guess he's not here, let's go Clancy", immediately afterwards a real cop shows up (with exactly the same voice that Bugs uses) and they go through exactly the same routine but this time when he turns on the gas they run out and beg themselves to be arrested. They appeared next in Bugsy and Mugsy in which Bugs makes Mugsy do things that cause him to get hit by Rocky and their fighting eventually leads to them getting arrested, Mugsy looked completely different from the previous short and depicted as being thinner and having a big chin.
They last appeared in The Unmentionables in which Bugs Bunny is an undercover detective come to arrest them he does so by trapping them in cereal boxes, in this appearance Mugsy looked like he did in Bugs and Thugs.
They make a very small cameo in The Looney Tunes Show. They appear in a book of people that the police have arrested before. There are other older characters in there like Hugo.