The robbery happened around 11:35am at the Wells Fargo Bank located at 11102 Scarsdale.
According to an FBI release, the suspect was "sporting a rather unusual long Abraham Lincoln-like beard."
Officials said the man entered the bank and handed a teller a threatening note demanding money. After passing the note, he lifted his shirt to display a pistol packed in his waistband, investigators said.
The man fled the bank on foot after getting a small amount of cash -- less than $100, authorities said.
No one was injured.
The Abe Lincoln Bandit is described as a white male, 5 feet 9-11 inches tall and 180-210 pounds with dark brown hair and a long, dark brown "Abraham Lincoln-like" beard. He wore a dark cap and a dark shirt with white stripes.
Anyone with information that could help investigators is urged to call the Houston office of the FBI at 713-693-5000 or Crime Stoppers.
Crime Stoppers will pay up to $5,000 for any information called in to the 713-222-TIPS (8477) or submitted online at www.crime-stoppers.org that leads to the filing of felony charges or arrest of the suspect(s) in this case. Tips can also be sent by text message. Text TIP610 plus your tip to CRIMES (274637). All tipsters remain anonymous.