While watching episode 3 of season 2 of "Jack Whitehall: Travels with My Father" I came across the the following sentences, all by the same native (British) English speaker (aged 78 at the time of this writing):
Would you tell her, I'm trying to find him a wife? [...] I'm looking for an attractive young woman. And also, ideally, somebody who goes like a rattlesnake.
That question has apparently been asked over here before prior to the release of season 2 of the show, but the answers there are all just guesses. I'm thinking perhaps with the wider audience at StackExchange I can get an authoritative answer here with additional examples of its use and meaning.
My first guess from the context was also that this carried some kind of sexual connotation, perhaps, but oftentimes as non-native speakers idioms are lost on us.