We never made a hypergoblin like you are describing, but in my college campaign, the DM did once throw in a boss with as many templates as he could find that would fit together. It was a wizard's failed experiment in manipulating quintessence (in this campaign, a miracle substance left behind as residue from time travel, with wide magical/alchemical uses) and using it to infuse a living being with extraplanar energies.
Basically he ended up with a swollen, misshapen Lovecraft-style drake with all kinds of demonic, elemental, psionic, construct, and Gods know what else traits. It was highly resistant to most damage and had a plethora of special attacks.
I'm pretty sure the critter's frothing insanity was the only thing that saved us. I can't remember how we killed it but I think it inolved a Portable Hole and Mordenkainen's Disjunction...