In Batman: The Animated Series, Rhino and Mugsy were two thugs who joined the Ventriloquist's gang.
Named for his hulking size and a tattoo on his right arm, Rhino was the first to join the The Ventriloquist's gang. When his sleeve was partially ripped in a robbery, Batman was able to identify him by the tattoo and confronted him. Rhino didn't tell him anything, but afterwards rushed to Scarface, revealing the villain's identity to Batman. Partner with Rhino, Mugsy was also one of the Ventriloquist's henchmen. Being the more subtle of the duo, Mugsy and Rhino assisted their boss in two occasions. The first one was when Scarface committed several heists with clockwork precision, which attracted Batman's attention.
Rhino and Mugsy worked for the Ventriloquist on a number of occasions, first when the Ventriloquist planned a series of heists with clockwork precision, and later when the boss enlisted Catwoman to help steal Veronica Vreeland's rare stuffed animals. On both these occasions, Rhino and Mugsys' raw power was unable to beat Batman's finesse. In The New Batman Adventures, when the Ventriloquist was released from Arkham Asylum with a clean bill of health, Mugsy and Rhino waited for Scarface to emerge. When it turned out that he wouldn't, however, they hired Hips McManus to impersonate Scarface and resurrect the gang. However, the real Scarface was upset with them and attempted to kill them, but Batman and Batgirl saved them and sent them to Blackgate Penitentiary.
As in the comics, Mugsy was apparently the only member of Scarface's gang who fully understood that the Ventriloquist and Scarface existed as two separate personalities in the same body (that of the Ventriloquist), as evidenced by his refusal to execute the Ventriloquist on Scarface's orders after Scarface suspected him of betrayal.