Jacob In Twilight: New Moon
Clearly, you need to use CGI when you want to depict something that does not exist in real life.
However, it says a lot about the talent of the SFX team when the members of the audience start to wonder where they found such a big wolf to play Jacob’s werewolf form!
Thanos In Avengers: Infinity War
The hardest part of being in a motion capture SFX team is balancing the animation and the expressions made by the actor.
We are sure the team was glad that Josh Brolin can make such distinct expressions! That probably made things somewhat easier.