This is a so-called 'Deep Fake' where the face of the original actor, Matthew Broderick, was replaced with an appropriately aged Arnold Schwarzenegger. While the voice was done by the video creator, the impression was very good.
I have seen some deep fakes that were also able to recreate the voice of the person being 'faked'. This is both neat - I'm a tech geek and like stuff like this - and scary at the same time. Being able to create convincing videos of anyone saying anything means it would be easy to destroy reputations and end careers - political or otherwise - something that should scare everyone.