The skills of earth tunneling and water escape are indeed the essence. Or rather, the Skeleton Hydra doesn't have a single truly useless skill; even those with smaller impacts don't exist, all are the essence among essences.
As the name suggests, earth tunneling allows one to move underground, and the Skeleton Hydra can do the same.
However, the true purpose of this skill is not this but to allow the Skeleton Hydra to move on the ground.
Yes, moving on the ground. In fact, the structure of a Nine-Headed Serpent is already very unique, not suitable for activity. Nine heads are a burden for the body.
The same goes for the Skeleton Hydra. With so many strong heads, it is not easy for the body to move. Under normal circumstances, no matter how flexible the Skeleton Hydra is, its body cannot be agile.
Slow in movement and clumsy in body rotation, this is the real norm.
But with the earth tunneling skill, the ground becomes a special environment for the Nine-Headed Serpent.
