Machete
From Tardis Wiki, the free Doctor Who reference
A machete was a large knife.
Sontarans sometimes used them. (TV: The Sontaran Experiment).
The Tenth Doctor and Rose Tyler used machetes to cut foliage while searching for the Dramos. (COMIC: Blood and Tears)
Chris Cwej used one to cut open coconuts when he and the Seventh Doctor were stranded on an island. (PROSE: No Room)
