Odd? Maybe - Memorable? Definitely!
In the very first campaign I ever ran back in '83, our Chief MO was Half-Vulcan, Half Human like Spock...but was raised by his mother on Earth. His father perished aboard the all Vulcan U.S.S. Intrepid.
He didn't know how to mind meld, had the "bad habit" of smiling or laughing at jokes and basically halved all the Vulcan bonuses and penalties. He wasn't designed as a power character, only a cool character.
Other mixes from our games...
Human/Caitian
Klingon/Vulcan
Andorian/Human (See Among The Clans: The Andorian Sourcebook-The Andorian/Human crossbreed in that book was inspired by a PC)
AndorMan
Powers and abilities for beyond those of mortal Andorians