I'm no lawyer, but I found this in the online Texas statutes cut and pasted below.
Note that it would be a felony in season also, if done without landowner permission.
SUBCHAPTER B. PROHIBITED ACTS
Sec. 61.021. TAKING WILDLIFE RESOURCES PROHIBITED. Except as permitted under a proclamation issued by the commission under this chapter, no person may hunt, catch, or possess a game bird or game animal, fish, marine animal, or other aquatic life at any time or in any place covered by this chapter.
Acts 1975, 64th Leg., p. 1405, ch. 545, Sec. 1, eff. Sept. 1, 1975. Amended by Acts 1981, 67th Leg., p. 506, ch. 213, Sec. 2, eff. Aug. 31, 1981; Acts 1981, 67th Leg., p. 2740, ch. 748, Sec. 3, eff. Sept. 1, 1981.
Sec. 61.022. TAKING WILDLIFE RESOURCES WITHOUT CONSENT OF LANDOWNER PROHIBITED. (a) No person may hunt or catch by any means or method or possess a wildlife resource at any time and at any place covered by this chapter unless the owner of the land, submerged land, or water, or the owner's agent, consents.
(b) Except as provided by Subsection (c), a person who violates Subsection (a) the first time commits an offense that is a Class A Parks and Wildlife Code misdemeanor and is punishable in addition by the revocation or suspension under Section 12.5015 of hunting and fishing licenses and permits.
(c) A person who violates Subsection (a) the first time by killing a desert bighorn sheep, pronghorn antelope, mule deer, or white-tailed deer commits an offense that is a Parks and Wildlife Code state jail felony and is punishable in addition by the revocation or suspension under Section 12.5015 of hunting and fishing licenses and permits.
(d) A second violation of Subsection (a) shall be classified as one category higher than the first violation or a Parks and Wildlife Code felony, whichever is lesser, and is punishable in addition by the revocation or suspension under Section 12.5015 of hunting and fishing licenses and permits.
(e) A third or subsequent violation of Subsection (a) shall be classified as a Parks and Wildlife Code felony and is punishable in addition by the revocation or suspension under Section 12.5015 of hunting and fishing licenses and permits.
Acts 1975, 64th Leg., p. 1405, ch. 545, Sec. 1, eff. Sept. 1, 1975. Amended by Acts 1981, 67th Leg., p. 507, ch. 213, Sec. 2, eff. Aug. 31, 1981; Acts 1981, 67th Leg., p. 2740, ch. 748, Sec. 3, eff. Sept. 1, 1981; Acts 1997, 75th Leg., ch. 1090, Sec. 1, eff. Sept. 1, 1997; Acts 1997, 75th Leg., ch. 1256, Sec. 73, eff. Sept. 1, 1997; Acts 1999, 76th Leg., ch. 959, Sec. 6, eff. Sept. 1, 1999.
Amended by:
Acts 2005, 79th Leg., Ch. 1002, Sec. 2, eff. September 1, 2005.