You probably seen alot of old games have this follow camera on specific persons.
Some of them have a window you can toggle and put in a corner that is apart from your normal camera. It will follow what you choose(Heartling) While you can still look around and stuff with your normal camera.
And if you dont wanna follow the heartling/creature anymore. You just close the window.
Good idea will be to make the window popup resizable. So you can choose your own size.
Also remember to make it movable.
With this. I can keep an eye on whatever i want. While still looking around the world and doing stuff.