. . . . "Portrayed by Pat Houtchen [Episode #88: \"Snoopy Smart vs. the Red Baron\"]. Reality Check: The original Leviathan was an Old Testament sea monster. By extension, the word refers to anything large or massive."@en . "Portrayed by Pat Houtchen [Episode #88: \"Snoopy Smart vs. the Red Baron\"]. Reality Check: The original Leviathan was an Old Testament sea monster. By extension, the word refers to anything large or massive."@en . "Dr. Leviathan"@en .