Tex. Prop. Code § 112.004
A trust in either real or personal property is enforceable only if there is written evidence of the trust's terms bearing the signature of the settlor or the settlor's authorized agent. A trust consisting of personal property, however, is enforceable if created by:
Added by Acts 1983, 68th Leg., p. 3332, ch. 567, art. 2, Sec. 2, eff. Jan. 1, 1984.