I was thinking more along the lines of Twattycakes, for the Yahtzee reference. Although that could make for some awkward moments...
other suggestions:
Lord of the Fin (obvious nerd reference)
Whalebait (you never know what happens when you flush a fish down the toilet)
Minnow (just because)
Turd (it WILL swim around in its own toilet)
Lord Bottomtooth, High Ruler of Fishtonia (keeping with the royalty names)
Gillbo Baggins (another nerd reference)
Turkeyburger (???)
The Commissioner (might be funny to hear that every once in a while)
MegaShark (best SyFy creature in recent history)
King Ghidorah (well, it is a King beta)