Basiliskan

Basiliskans, later renamed Lagartoz War Dragons, are a species of hyper intelligent reptilian dragon-like creatures that are native to the planet Basilisk in the Core Worlds. Basiliskans are known for being incredibly sapient, considered one of the most intelligent species of reptile in the Star Wars Universe, as the species is responsible for the creation of several mechanical devices, most famously the Basilisk War Droid. During the New Sith War, the Basiliskan were taken over by the Mandalorians and used as mounts to use in battle against the Sith Order during the war. Due to this, several Basilskan went insane, losing their sapience and became deranged, mindless beasts completely loyal to their Mandalorian masters.