After he got to the water surface, he saw that the whole cavern ceiling was covered with some quarts that were of many different colours, but all illuminated the cavern and were as if stars in the bright sky.
Kyle was not expecting anything like that, but what nearly made him go back to under the world was a huge worm that was drinking from the water that Kyle was in. The warm was a little smaller than the biggest tunnel Kyle has dropped through, but it was still extremely shocking.
The worm seemed to completely ignore Kyle that caused a stir in the water and carried on drinking with no emotions.
Kyle didn't know who stole his items and was still mad, that is why he chose this worm to be his culprit.