"Anti-teleport Cave" 

After warning everyone, only then did the plant-tamer girl ask the mermaid to approach their target as fast as possible. 

"Senior, we have to approach the cub or we can send the grass to knock out the cub first before we kidnap it. How is it?" 

The grass could survive under a certain degree of water pressure so the group only had to manipulate the grass to 'swim' to the sleeping cub in the nest and quietly knocked out the cub while it was still sleeping. 

The group didn't want to wake up the cub at all, afraid that they would face another unexpected situation or something. 

The mermaid thought for a while and chose to send out the grass while they remained at a safe distance so that the cub wouldn't be alerted at all. 

After discussing things, the plant-tamer girl finally used her plant-taming ability to send out the knock-out grass from their dual barriers.