Or maybe the prayers of The Pattimuss were answered.
I like that idea.
Or, maybe, perhaps, he, ol guppybutt, realized that while he may be all "that" to him, he wasn't much to others and he left.
Or, maybe some nefarious plan put into play was so effective that he simply left.
Or, like an over inflated balloon, it's possible he simply popped due to an inability to regulate the pressure of his ever expanding cranium.
But, and here's the key, who really cares?