He should have been called El Choo-po.

Mexican cartel kingpin Joaquin “El Chapo” Guzman ran a cocaine train all the way from Mexico to New York City, a witness testified Monday.

“Chapo decided who could use the train route,” cartel member turned informant Tirso Martinez Sanchez told Brooklyn federal jurors in Guzman’s drug trafficking trial.

Martinez said he began overseeing the choo-choo operation around 2000, after a predecessor shot himself in the face, and another died on the operating table during plastic surgery.

The tankers would transport cooking oil into Mexico under the guise of a legitimate business, where the oil would be siphoned out and secret compartments on either end would be stacked with kilos of cocaine, he explained.

Workers would then add an inch or two of oil to the bottom of the container to discourage customs from crawling in to look around on their way back north. They also covered their tracks by dabbing the kilos themselves with grease to throw off the scent for drug-sniffing dogs

In all, the tankers netted the Sinaloa Cartel $500 million to $800 million in cocaine sales from New York, Los Angeles and Chicago between 2000 and 2003, the 51-year-old testified.

And El Chapo was a regular Choo Choo Charlie, the former drug runner said, noting that the kingpin had boasted about “inventing” the train routes.

This isn’t the first time jurors have heard about Chapo’s love of trains — a former lieutenant told the court Chapo used a “little” locomotive to travel around his personal zoo.

Martinez guessed that made between $15 to $20 million working with Chapo, who he called “patas cortas,” or “short legs.” He said he shipped the money back to Mexico, where he lived, by purchasing watches and jewelry in Manhattan and sending the bling home.

And that was before losses. While others have testified Chapo blew his money on a diamond-encrusted pistol, a gold-plated AK-47, and jets, Martinez, nicknamed “El Futbolista” for his love of the sport, spent his on horses, cockfighting, and soccer teams, he said.

In addition to gambling, the drug trafficker said he’d also had three plastic surgeries to change his appearance — though his doctor aborted the third because of his high blood pressure.

Martinez appeared nervous when he first took the stand Monday, misspelling his own name for the court reporter.

He soon reduced the gallery to giggles when, asked to identify the 5-foot-6 El Chapo, he said he was the “short” guy wearing the blue shirt.

Martinez testified that the cartel’s cocaine trains would pull into a warehouse in New Jersey, and then box trucks would transport the kilos to a Big Apple warehouse.

Once in Gotham, Martinez said his men would meet with distributors at McDonald’s or Burger King, at tables inside the fast food chains, and leave drug-packed cars in the parking lots outside.

“We would tell them what car held the drugs, and hand them over the keys,” he said.

Martinez said he stopped working with the Sinaloa Cartel after three of his warehouses were raided by cops, and he was under ‘too much pressure,” following the $100 million loss of cocaine.

“They wanted to kill me because I had lost the train route, that means of transport,” he told jurors. “I just didn’t want to keep going.”

He said he ghosted the kingpin and his associates, and miraculously survived long enough to be arrested in 2014 and extradited to Brooklyn, where he ultimately pleaded guilty to importation and distribution charges.

Guzman faces life behind bars if convicted of operating a continuing criminal enterprise, murder conspiracy, and other charges.