Wallach's first film role came as Silva Vacarro in the then-controversial 1956 black comedy Baby Doll ,and later appeared in such films as The Magnificent Seven, How the West Was Won, and the Joseph Conrad adaptation Lord Jim. However, Wallach's career peaked with the unforgettable role of Mexican bandit Tuco Ramirez, or the Ugly, in Sergio Leone's iconic 1966 spaghetti western The Good, the Bad, and the Ugly.
In The Good, the Bad and the Ugly, Wallach co-starred with fellow actor Clint Eastwood. Eastwood was in talks to play Two-Face in the 1966 Batman show along side Wallach as Mr. Freeze. However, the show was cancelled before anything was finalized. Additionally, Many fans have expressed interest in seeing Eastwood play Batman in the 1970s, however these plans ideas were unrecognized.
The Good, the Bad and the Ugly was released in Italy in 1966, the same year as the first season of Batman.