The actor told BANG Showbiz that while he hopes the Time Lord will someday face dinosaurs, he understands that the creatures might prove too costly for the show's production team to create.
"I'd quite like to go and see the dinosaurs, but I imagine it would be really expensive," he said. "That would be really cool. I'd also love to go under the sea - that would be fun."
The third incarnation of The Doctor (Jon Pertwee) faced prehistoric beasts alongside his companion Sarah Jane Smith (Elisabeth Sladen) in the 1974 serial 'Invasion of the Dinosaurs'.
Smith added that he hopes The Doctor will at least bring a pet on board the Tardis at some point.
He joked: "We should get him [a] sort of pet. An owl. An otter. Oswald the otter."
The Doctor Who one-off holiday special 'A Christmas Carol' will air on Christmas Day on BBC One in the UK and BBC America in the US.