XM-X1 Crossbone Gundam X-1 Kai Kai "Skull Heart"

The Crossbone Gundam X-1 Kai Kai "Skull Heart" is a mobile suit which appears in the manga Mobile Suit Crossbone Gundam.

History
After the XM-X3 Crossbone Gundam X-3 was destroyed in battle with Crux Dogati, and the first conflict with the Jupiter Empire over, the XM-X1 Crossbone Gundam X-1 Kai fell into Tobia Arronax' hands and was modified into the X-1 Kai Kai "Skull Heart" (as it now featured a skull & crossbones on its chest much like the X-3). Its new weapon was the Peacock Smasher, which is a beam crossbow composed on 9 beam guns: a main powerful beam gun serves as the main body, with four on each side lined up across the "bow". In this mode, it was further enhanced into its Full-Armor mode, the XM-X1 Full Cloth. The Full Cloth replaced the Anti Beam cloth, and mounted even more thrusters, as well as provide further offensive capabilities with a reactor-fed Hi-Muramasa Combination weapon (see X3 for details) and the Pile Bunker, a large shield mounting two powerful piledriver spikes. With this armor it was also nicknamed the "X-4". Tobia used his suit to fight against remnants of the Jupiter Empire and other threats his crew came across.