You have to make a Gordo explode by by feeding it too much of the food type that it wants. Gordo Slimes are giant slimes that provide either a Slime Key, to allow you into new areas, or a teleporter, which allows quick access between the Ranch and each area
However, I don't recommend playing in this mode unless you are really struggling with them, as there are two achievements related to the Tarr. In casual mode, the Tarr do not appear, as Largos cannot eat plorts. This will destroy any slime (Tarr or not). Another trick to getting rid of them in smaller number is to vac one up then fire it into the Slime Sea. At night they gain more health and require two splashes the first will remove their rainbow colouring, and their ability to replicate, then the second will obliterate them. However, they are weak to water, and during the day a single splash is enough to destroy them.
Due to this, they can potentially spawn anywhere at any time of day, and if one of those places is inside your Ranch, you could potentially lose all you slimes if you're really unlucky.
They will consume other slimes and replicate when they do, leading to an almost endless amount of them. The Tarr are hostile to absolutely everything, including yourself. Largo slimes that eat a plort that it does not produce transform into the Tarr, the main source of danger in the slime world.
