The "Super Deadly Sins" were added in the Wrath of the Lamb expansion and will sometimes appear instead of the regular version of the accordant Deadly Sin, including sins appearing outside miniboss rooms in later levels. They also appear to be slightly larger than their normal counterparts.
A unique variant of Super Pride exists, known as Ultra Pride was added into the Wrath of the Lamb DLC in Version 1.3. Upon defeating him, the achievement/secret and the Trinket The Left Hand is unlocked.
The health of the Sin you are facing varies, depending on the current floor you are at.
These enemies can appear in normal rooms of The Womb/Utero and onward but unlike regular bosses, they can drop Pick Ups and Items associated with them when they're defeated (if there are multiple sins in the same room, items spawn when the last one is defeated).
There are items that the player can collect throughout the game, giving Isaac similar attacks and effects as the Seven Deadly Sins. (For example, Dr. Fetus = Wrath, The Virus = Lust, The Inner Eye = Greed, etc.) Some of these items can be dropped when the sin is defeated.
Isaac can bomb the door and walk away from a fight with any Sin if he has flight.