The mud statue was hidden inside the swamp. When Shi Yan and Shang Ying Yue were fighting, it had started to collect the Hundred Kalpa Soul Thread.
When the unknown brothers came, the mud statue stopped for a while, but it couldn't hold its desire for a long time. It tried to collect more of the Hundred Kalpa Soul Thread right after that.
The way he was collecting the Hundred Kalpa Soul Thread wasn't similar to Shang Ying Yue's method. The mud statue opened his mouth to spurt out a muddy brook, which acted like a small, soft hand that grabbed the sparkling blue-ice silky threads and shoved them into his mouth.
This mud statue seemed to have mastered the power of mud and sand, especially the powers of Earth. As he was swallowing some of the Hundred Kalpa Soul Thread, the amount of Hundred Kalpa Soul Thread on the ground was reduced.