You yourself are a legal entity.

When you create a trust, you create a new legal entity separate from yourself where you, if you're the trustee, can specify what happens to the assets in the trust.

Most trusts terminate upon the death of the trustee, BUT not always.

Laws are in place in several states that allow for perpetual trusts. I believe South Dakota lead the way here. So, if you have substantial assets, they can remain in the trust indefinitely, even after your passing.

For example. Richard places the western half of Iowa he owns into a perpetual trust. Upon his death, the only thing that happens is he is removed as a trustee. Other trustees remain or successor trustees can be added.