It depends on what each monster achieves in adding to its respective game. The question I want to answer in this post is: which monster was better? The preliminary answer is, “it depends”. Without these particular monsters, neither game would have been the same. Still, ask any player who has experienced RE2 or TLoU2 to recount the most striking parts about either game and they are bound to mention Mr X (officially named Tyrant, but I’ll refer to it as Mr X) and the Rat King. Encounters like the first licker in RE2 or the stalkers in the office building during Ellie’s Seattle Day 2 in TLoU2 are unsettling and make the games more memorable.
Ditto for The Last of Us (Part I and II) if you were to remove both infected and human enemies. What’s a horror game without its different sources of horror? If you remove the zombies, lickers, sewer creatures and other G- and t-virus abominations from Resident Evil 2, you are left with a third-person item collection and puzzle game.