Maston

Mastons were large predators native to Sentimenous Virgo. They generally weighed around 120 kg and were around 2.10 metres tall. Mastons were large and hairy and had a powerful tail. They could easily overpower a Human, but they weren't especially intelligent.

A sexually aroused Maston secretes an airborne toxin which paralyses any animal lifeforms in its immediate vicinity. The exact range of this effect is unknown. This is speculated to be an evolutionary adaptation designed to ensure that an exhausted post-coitus Maston will not have to look too far in order to find its next meal. (DWN: ''Slipback (novelisation) )

The Mastons were driven to extinction millions of years ago when their planet was destroyed. The computer of the Vipod Mor brought a Maston forwards in time to attract a Time Lord and to distract the crew. (BBCR: Slipback)