Add the Age Table
Middle age: 0, Old: 0, Venerable: 0, Maximum Age: +0.
This applies to every campaign where elves and/orcs are anything like the ones in D&D as described in the D&D (Grayhawk), Forgotten Realms, and about every other campaign setting I could possibly mention, and another where such bastards are commonplace that world better be no planet with a connection to the great wheel, lest the Elven Imperial Navy just decides to blast the whole globe.....
I think that both races involved would slay such an abomination should it ever be born. Chances are quite high that the creator gods of both races (Corellon Larethian for elves and Gruumsh for orks in both Grayhawk and FR) have made it impossible for the two races to be interfertile. If I created the elves I would have made sure that they're genetically incompatible with everything with tusks in the face and green skin!
Should such an abomination really be necessary in the campaign (I think that this would be a real sick place), make it +2 Str, -2 Int, -2 Dex, Darkvision and Low-Light vision, +1 on search, spot and listen, immunity to sleep and +2 save bonus agains Enchantment, but neither orc blood nor elf blood: outcasts as they are, they would be rejected by magical weapons of both races.
They should also be considered outcasts in both elf and orc cultures (or what passes for cultures for an orc), so no orc or elf home region.
Ravored Class: Barbarian. They inherited their orc parent's physical nature, and with that comes the bias towards brute force.