Ivan “Pudge” Rodriguez
The simple answer to what makes Pudge one of the toughest players to have ever played the game is his durability and endurance. It takes a lot of a player to catch a single ball game – let alone to catch 21 seasons worth of them, which is exactly what Pudge did. He holds the record for most amount of seasons as a catcher, and even though he bounced around from six different teams throughout his career, Pudge had a major impact on each of them. Furthermore, he holds the best caught stealing percentage (45.68%) for any catcher ever, so if that doesn’t make him threatening, I don’t know what does.