He name is Rob McNaughton and you can find him in the credits of Starcraft. The art piece is dated 7.19.96!! and it's titled Rob’s Mech.
» Rob’s Mech
» Warpig
Now this one is also well known, check out the zerglings and the proto-Kerrigan, it is titled KeryLone. The meaning behind the name of this title?
» KeryLone
You can check some of his other art work at his gallery, you will find some of his work related to warcraft and non blizzard motifs.
Links
Chaingunstudios.com - Rob McNaughton
Our forums - More of Rob's work