Superman (1939). Certain materials such as lead can block his X-ray vision. Superman can project beams of heat from his eyes which are hot enough to melt steel. He first used this power in "Superman" #59 (1949) by applying his X-ray vision at its highest intensity. In later stories, this ability is simply called "heat vision". Superman can hear sounds that are too faint for a human to hear, and at frequencies outside the human hearing range. This ability is introduced in "Action Comics" #11 (1939). "Action Comics" #1 (1938) explained that Superman's strength was common to all Kryptonians because they
DC animated universe (comics) League Unlimited" comics did use many characters from the DC Universe, some characters never made it to the screen. Those that did not appear in the television series are listed below: The entire Marvel Family (except for Captain Marvel, who made a one-time appearance) were unable to appear on "Justice League Unlimited" due to legal reasons. DC animated universe (comics) While Batman and Superman had their own animated series and comic book follow-ups, the rest of the characters in the would appear in the following comics often. The Batman Adventures was created as a comic book tie-in to and The