WATCH: Stephen Colbert ridicules ‘Oompa Loompa’ Trump’s screaming banshee immigration speech

Stephen Colbert was baffled by the way Donald Trump went from subdued and almost statesman-like in Mexico to screaming like a banshee about immigrants just hours later in Phoenix.

"The last 24 hours of Donald Trump has been an emotional roller coaster, and you must be this crazy to ride," Colbert said, measuring a height at about ear level to himself.

Trump went to Mexico on Wednesday seeking an ally, barely looking up as he read prepared remarks alongside Mexican President Peña Nieto, but hours later -- back on American soil -- he lashed out angrily at "violent" immigrants during a speech to supporters in Arizona.

The Republican presidential nominee's speech was so terrifying that Colbert ducked to the floor in fear, poking his head up only after Trump's panicked litany of dreadful warnings had ended.

"Is the bad man gone?" Colbert said. "Do I have time to change my pants? Because I am in code brown right now."

Colbert said you couldn't really call that Wednesday night horror show a speech, since Trump screamed all of his awful predictions about chaos and lawless violence, so he proposed calling it a screech.

"I don't understand how he changes emotions so quickly," Colbert said. "He went from Mr. Cool in Mexico to thermonuclear in, like, an hour. I'm starting to think there might be more than one Donald Trump."

"Here's my theory," he continued. "Trump is actually three Oompa Loompas standing in a human pyramid inside his suit -- one here, one there -- and they take turns on who gets to be the head every day. One of them is reasonable, two of them really don't like immigrants."

Watch the entire segment posted online by The Late Show With Stephen Colbert: