Dancougar

Dancougar (超獣機神ダンクーガ, Chōjū Kishin Dankūga) is a Japanese super robot anime television series produced by Ashi Productions, and aired for 38 episodes from April 5, 1985 to December 27, 1985, followed by 4 OVAs. The anime was licensed by Central Park Media under their Software Sculptors label in 1995, and was released on subtitled VHS. A sequel entitled Dancougar Nova (獣装機攻ダンクーガノヴァ) aired in Japan on Animax in 2007.

Plot
Emperor Muge Zarbados and his Empire of Death decide that their next conquest will be the faraway planet of Earth. Muge becomes even more fearsome because of Shapiro Keats, a power-hungry Earthling-turned-traitor. It's up to a team of four soldier task-force (Shinobu Fujiwara, Sara Yuki, Masato Shikibu and Ryo Shiba) to pilot the four Beast Mecha (Eagle Fighter, Land Cougar, Land Liger, and Big Moth [a mammoth mecha]), which can combine into the giant mech Dancougar.

Dancougar Nova
The series takes place in 2107, 200 years after the first series. Peace on Earth has yet to be reached not from major world wars, but from small-scale ware conflicting all over the globe. But a large mysterious robot appears like God to "protect the weak" and end conflict with its existence to remain a mystery. Neither enemy or ally to humanity, the robot only stands for the planet's protection while retaliating against an enemy of unknown power. And its name is Dancougar Nova.