Stephen Colbert mocks Trump's speeches as so nutty they 'ran crazy off a cliff into Coo Coo Canyon'

Stephen Colbert can't help but notice several similarities between a man hit over the head with a brick and President Donald Trump.

During the president's latest rally in Montana, he rambled on about Elton John, organs, records and a series of other musings including a DNA test he wants to "gently" give a female senator.

"And Trump is a real expert on DNA tests. He has performed dozens of them," Colbert said. He then pretended to be Trump demanding his son Eric take another DNA test to prove they're actually related.

The speech was "off script and on crazy," according to Colbert. "He just ran crazy off a cliff into beautiful Coo Coo Canyon."

The "Late Show" host couldn't help but recall  "when people were thinking Trump's brain might be on the fritz but then his doctor Ronny Jackson said it wasn't because Trump took a test where he successfully identified a camel. But then Dr. Ronny turned out to be a pill-popping dealer that drank on the job but then we never sent in another non-pilled doctor to test Trump's brain? Remember that?"

He noted this is the man that is picking the next Supreme Court Justice. Colbert couldn't help but mock Trump for still being undecided on his choice as of Sunday evening.

"I don't feel like doing this tonight," Colbert lamented in his Trump voice. "Why can't I just nominate Neil Gorsuch again? Give him two votes, double stuffed judge."

But when it came to Trump's tweet on Monday morning, Colbert couldn't help but laugh.

"What do you mean you have 'long heard?'" Colbert asked. "Are you still asking people what your job is?"

Colbert went on to do his own Trump speech pretending to be a person with their own head injury.

Watch Colbert's full opener below: