"I don't think we should be doing this," the 77-year-old actor, known for his iconic voice, told the host after breathing in some helium from a red balloon. "It's very undignified."
"Your voice sounds great," an amused Fallon assured Freeman.
Upon thanking the actor for coming on the show, the late-night host asked if Freeman would ever come back on the Tonight Show. He responded, "I'm never coming back."