This is a northern quoll, very possibly a juvenile northern quoll.
Northern quolls are the largest known mammals to undergo semelparity, in this case male die-off. Much like the more infamous antechinus, northern quoll males go into a mating frenzy and die from exhaustion. This particular instinct can be suppressed with measure such as isolating the male from the relevant female pheromones, or giving him the snip. Or, as one antechinus researcher discovered, accidentally having their knackers ripped off while escaping from a trap.