Which animal left Steve Backshall close to tears?
31 August 2014 Last updated at 13:18 BST
Steve Backshall is going pole to pole for his latest mission - travelling from the Arctic to the Antarctic in search of the deadliest animals.
In his interview with Martin, Steve talks about Antarctica: "There are few places on the planet that are as exciting. Most of the animals there have never seen human beings."
He also recalls the moment he finally tracked down the animal he's been searching 15 years for - and how it left him close to tears.
Deadly on a Mission: Pole to Pole is on BBC One on Sunday evenings.