The Zillo Beast, sometimes referred to simply as «the Beast,» was a semi-sentient, reptilian species endemic to the planet Malastare. The Dugs believed this gargantuan creature to be extinct long before 21 BBY; during the Battle of Malastare, however, the last specimen alive was inadvertently unearthed by an electro-proton bomb used by the Galactic Republic.
Supreme Chancellor Sheev Palpatine sought to use the Zillo Beast’s indestructible hide to aid the Grand Army of the Republic. Shortly after the creature was brought to Coruscant for study, however, it broke free from its restraints and rampaged through the capital. In the end, the Jedi and Republic army were left with no other choice but to kill the Zillo Beast using a powerful toxin, the same one that had compelled it to ravage Coruscant, but in larger doses. Before the creature was killed, Palpatine ordered it to be cloned.
One Zillo Beast lived in Wild Space where it was worshiped as a god by the Benathy, though it was later killed by Kylo Ren.