Story highlights Word of Donald Trump's trip to Mexico sparks criticism online

Some respond with Twitter jokes, while others offer harsh words

(CNN) As word of Donald Trump's surprise trip south of the border spread, many Mexicans took to social media with a common refrain: "Is this a joke?"

But it wasn't long before they started coming up with jokes themselves about the controversial visit. Many also poked fun at Mexican President Enrique Peña Nieto, who has agreed to meet with Trump and whose popularity has been tanking.

"An advanced look of what we'll see tomorrow," one person tweeted Tuesday night, posting an image of the lead characters from the 1990s cartoon "Beavis and Butt-head."

Mexican actress Ana Brenda tweeted an idea, encouraging Peña Nieto to block Trump at the border.

"You will be a national hero," she wrote.