The Hollywood Reporter describes the elder Snart as "a cold-blooded, ruthless career criminal" who, having been released from prison, concocts a plan that will endanger Central City -- including his own children. Ironside will first appear in "Family of Rogues," the third episode of season two, alongside Captain Cold and Golden Glider.
Though mentioned, Lewis Snart doesn't really appear in the comics; because of his abuse, the young Snarts lived with their grandfather, who drove an ice truck. With Ironside attached to the role, however, it seems that the show plans to expand on and develop this character.
Ironside is no stranger to comic book casting, having lent his voice to animated series like "Batman," "Superman," "Justice League" and "Wolverine and the X-Men." He also played General Lane, Lois Lane's father, in several live-action episodes of "Smallville." He is most known for his appearances in classic films like "Top Gun," "Starship Troopers" and "Total Recall."