Activity Monitor: "Agent" using a lot of memory.

For what it's worth I am unaware of any Apple process by that name. macOS runs many agents but the only ones I am familiar with have more descriptive names.

That doesn't mean it doesn't exist, it just means I can't find it on any of the Macs I'm using at the moment. Perhaps it is related to Battle.net... a massively multiplayer game, I surmise?

You may wish to determine if the same process appears while using your Mac in "Safe Mode": Use safe mode to isolate issues with your Mac - Apple Support.

Hello Alstrup22,

It looks like it is related to the "Battle.net" app.

See some articles See your Mac processes in Activity Monitor - Apple Support

See memory usage for your Mac in Activity Monitor - Apple Support

Quit a process on your Mac in Activity Monitor - Apple Support

I could not see a process named as Agent in my Mac ( by just typing Agent in the spotlight search of activity monitor application ) .

Some third party application is running in your Mac .