While contemplating what to do now, another small bout of gas hits. Not even bothering to suppress it, you let it pass. You look behind yourself as the faint "phoomp" noise escapes. The ass mass remains the same, but your new tail stretches another six inches or so. After this comes some sort of understanding, perhaps on the genetic level, that your ass and tail has reached their full size. A small speck of hope hits you, as despite how large it looks on a human, your ass is nowhere near the size of a full elephant's. Even if more of you changes, you contemplate as you play with your new tail, you should still be able work in society, although it will be weird.
Of course, you had to go and tempt fate. No sooner than you thought the word 'change', a rumbling in your stomach draws your attention, and the bloated feeling returns. Something bubbles from the pit of your stomach, and although you try to keep it down, your efforts don't last long.
"Buuuuurp!"
The bloated feeling leaves fleetingly, but you barely have time to register the burp smells of elephant breath before it returns. While the next burp readies itself, you inspect your body. The smallest of beer bellies has started to press against your shirt. Your sleeves don't reach all the way to your wrists anymore, and your hands look larger compared to the cuffs. Looking behind you, your ass looks ever so slightly smaller, and isn't bulging out quite as much.
"Buuuuurp!"
You can see your beer belly bulge out a little further, pushing your shirt up a little. Now you can see the flesh underneath. While still as smooth as a human, it's definately looking more grey.
A third burp, and the bottom button of your shirt pings off, revealing more flesh, now matching the greyness of your ass. The top of your tattered pants are cutting into you, so you fumble with your fingers, now thicker than before, to undo your fly. Your new belly thanks you by flopping out futher. You know your trousers aren't safe yet, because you can feel them getting tighter. Another quick check of your ass, and it's comparatively about two thirds of the size it was before you started burping. A strange noise comes from your feet and you look down at your shoes, which have split open, one foot still socked, the other burst open, revealing large grey feet with unusually thick toe nails. You had better get back home Before this change completes and somebody spots a half human half elephant running around! So off you run, trying to keep down the fourth burp.