Originally controlled by Dr. Eggman during his attack on the Konoha during "The Chunin Exams". Afterwards, Tails was charge in see whaere did Eggman obtained it. Once rebuilt, Tails discovered that the Liger had a mind of it's own, which is surprising since most robots with it's own mind would go insane, but The Liger Zero is plain stubborn and rowdy. Until Ahiru, Daffy's Daughter climbs into the cockpilot and controls the Liger with no problem unlike who had a rough time riding.
The Liger Zero is stubborn at times and likes to go loose cannon. It has shown to be loyal with Team Sonic. King Mickey assumes that the Liger zero is like the keyblade and chooses it's weilder or this case pilot.