Fuck.
Jack realized what had happened just in time to roll out of the way of a goblin club that was now that size of a large tree compared to him as it came crashing into the ground, and stumbled to his feet just in time to leap out of the way of another.
As he ducked another tree trunk, he had just a moment to reflect on what had happened, and why things had gone differently than he expected, and then suddenly realized that he had absolutely no idea how to get back to regular size. For all his luck, he'd be stuck a pocket-sized fat kid in a Space Invaders shirt forever.
He reflected just a little too long, and suddenly found himself flying through the air from a club blow that less struck him, and more picked him up and flung him like a golf club performing a line drive. He sailed wildly through the air over several goblin heads, their big toothy grins laughing up at him as he hurtled through space like a badminton birdie. As if on cue, one of the other goblins jumped up and swung his club up at Jack, knocking him flying backwards with a resounding crack that knocked the wind out of Jack's chest and sent his head spinning.
Jack knew he had to do something, but about the time he started to get his thoughts in order, he was knocked back flying the other direction as the goblin attack devolved into a resounding game of Jackminton. Jack was grateful that the blows didn't hurt as badly as he expected, either as an advantage of being a lot smaller, or as a result of one of his wishes.
After a dozen or so swats back and forth, the goblins appeared to grow bored of the whole experience, and one of them swung up a net rather than a club, catching the now tiny form of Jack inside it and wrapping him up in it well enough that he couldn't move. The goblins, their target now trapped and incapacitated, set off down the trail in the direction Jack had been heading, several of them breaking out into baudy, tone-deaf songs that grated on Jack's hearing. He wondered aloud to himself if the singing wasn't somehow even worse than the beating.
The remaining goblins carried him for some time down the trail, up and down several rises and valleys, before the goblin in front squawked something in their harsh language, and the group stopped suddenly. Jack, from his limited and immobile vantage point, saw as several of the goblins nearest to him rushed to the front of the line, drawing their weapons and shouting things to several others, who followed suite.
He listened closely as several of the goblins shouted ahead of him, their voices raised in a tone and timbre that told him they weren't trying to be friendly with whatever it was they were reacting to. Then, for the first time coming to the new world, he heard another voice using words he recognized that wasn't Frumpkin. It was a woman's voice that sounded sweet enough, but with a distinct edge to it that simultaneously aroused and frightened him.
"That's far enough, snotlings." The voice said. Another voice, also female, spoke up immediately after in a tone softer and higher than the previous, "please just leave our farm. we don't want any trouble."
Jack was about cry out, when he heard one of the goblins near the front speak up, using common speech for the first time.
"Fuckk...ovff... vred... bvitch...", it said, seeming to struggle to get the words to come out correctly.
The first female voice laughed loudly for several long seconds.
"Make me!" She said.