I recommend the wiki page at gundam.wikia.com for a vast in-depth information about the mobile suit Gundam Astaroth. click the gundam wiki logo image on the right to take you there.
Gundam Astaroth is one of the 72 "Gundam" frames produced and used in the Calamity War, roughly 300 years ago. It is also one of 26 remaining Gundam Frames that survived the Calamity War and reported to be operational. The Warren Family, a family affiliated with Gjallarhorn, owned the Gundam Astaroth, but was forced to sell its armor and equipment when their financial situation went bad, with the suit's Gundam Frame eventually acquired by Tanto Tempo's Daddy Ted. The Astaroth was then restored to operational condition by fitting its frame with a mix of parts from other mobile suits, and an example of this is that its left forearm armor and left shoulder armor is from a UGY-R38 Spinner Rodi. The two side waist armors are called Boost Armor, which have a wide range of movement and help in the attitude/posture control of the mobile suit since the Astaroth's asymmetry affected its center of gravity.