Denise Petski Senior Managing EditorAmazon has drawn on six current or former cast members of The Walking Dead franchise to voice the iconic Guardians of the Globe in Invincible, the series based on Robert Kirkman’s popular comic book series of the same name.Lauren Cohan, Sonequa Martin-Green, Chad Coleman, Michael Cudlitz, Lennie James and Ross Marquand have joined the cast of the hourlong animated series from Kirkman, Cory Walker and artist Ryan Ottley.