Washington (CNN) -- The Boston Herald and its cartoonist apologized Wednesday for a cartoon that quickly drew criticism on social media for being racist.

A satire on the recent news that an intruder got farther into the White House last month than previously known, the cartoon depicts the intruder sitting in President Obama's bathtub, asking him if he has tried the "watermelon flavored toothpaste."

Critics quickly pounced on the watermelon aspect of the cartoon, arguing the cartoonist was playing off a stereotype that African Americans are particularly fond of the fruit.

The cartoonist, Jerry Holbert, said on Boston Herald Radio the watermelon reference was inadvertent. He argued he was "naive" about any racial undertones and "wasn't thinking along those lines at all."

Holbert said he used the watermelon flavor because he found "kids Colgate watermelon flavor" toothpaste in his bathroom at home.

"I want to apologize to anyone I offended who was hurt by the cartoon," Holbert said. "It was certainly, absolutely, not my intention."

The Herald also issued an apology: "His cartoon satirizing the U.S. Secret Service breach at the White House has offended some people and to them we apologize. His choice of imagery was absolutely not meant to be hurtful. We stand by Jerry, who is a veteran cartoonist with the utmost integrity."

A syndicated version of the cartoon uses the term "raspberry" instead of watermelon. Holbert said the syndicate called him Tuesday night asking if they could change the flavor.

Pressed Wednesday on whether Holbert should have called the Herald after his talk with the syndicate, Holbert said, "I wish I had done that."