42 is not the only answer!!!

'X' is a fictional character and the main protagonist of the 'Y' series. 'X' is a combination spy, special operations agent and mercenary of FOXHOUND, a fictional black operations and espionage unit. He is repeatedly tasked with disarming and destroying the latest incarnation of 'Y', a bipedal nuclear weapon-armed ______. Japanese voice actor Akio Ōtsuka voices 'X' in Japanese, while actor and screenwriter David Hayter provides the English voice of the character.

Identify 'X' & 'Y'....

'X'-Snake,'Y'-Metal gear