John Riddell was the big game hunter who got to hunt one of the biggest types of game in existence: an array of huge, deadly dinosaurs! We can't be certain when John Riddell first met the Doctor. Certainly, he had known the Time Lord prior to their adventure on the Silurian ark, expressing his fireside chagrin that the Doctor had disappeared seven months earlier on the flimsy pretext of ‘popping out for some licorice’!
Riddell is charismatic, fearless and capable of adapting quickly to new environments. Far from being unnerved by landing on a vast interstellar craft packed with dinosaurs, he relished the expedition, delighted by the opportunity to pit himself against some pre-historic predators. His stance on females was less heroic, however, and he viewed women through chauvinistic eyes – understandable as he grew up in the Victorian era.
He came to respect Amy and his feelings towards the Egyptian ruler were evident in his anger when Solomon moved to take her as his bounty. Our last sighting of Riddell was on the African plains, beneath the stars with Nefertiti by his side.