Jason Trask was a major villain on Lois & Clark: The New Adventures of Superman. He appeared in two episodes.
Jason Trask headed Bureau 39, a secret government organization that investigated perceived alien threats. Trask believed that Superman was the first agent of an alien invasion. His group discovered the spaceship that Superman had arrived on Earth in. Just after Superman's arrival in Metropolis, Trask took control of the Daily Planet building and interrogated the staff for information on Superman. This caused his superiors to send in George Thompson to reign in Trask and throw Lane and Kent off the trail. However Trask's obsession made him unwilling to listen to reason and so he killed Thompson. When Lois and Clark snuck into his base, thanks to help from a former member who found Trask repugnant, he used them as bait to lure in Superman so he could kill him. His plan failed and he was forced to pull out to avoid capture.
He later appeared in Smallville after the discovery of a strange rock found in the same field as the space ship. Understanding that the radioactive meteorite came from Krypton, he attempted to use the rock to kill Superman. During this scheme, Trask discovered that Clark and Superman were the same person. As a result he attempted to not only kill Clark, but his parents for harboring him. Subsequently the main fragment of the meteorite was destroyed and Trask was killed by the local Sheriff. Only Clark Kent and his parents knew of its true existence. Clark and his partner Lois Lane reported on the incident in The Daily Planet and described Trask's delusions of a fabled rock that could kill Superman. For the sake of the article, Lane and Kent devised the name "Kryptonite" to refer to the rock.