The Slither Pit is an arena located inside of the Hypnobrai tomb. It is a Serpentine event in which two or more fighters can compete for leadership, settling disputes, or general entertainment. The first Slither Pit was seen in the Hypnobrai tomb in episode 2.
When the Hypnobrai were sealed away in their tomb centuries ago, it is presumed that they would host frequent Slither Pit battles for entertainment.
When Skales challenged Slithraa, who had earlier accidentally hypnotized himself into obeying Lloyd Garmadon's command, for leadership of the tribe and the staff, a Slither Pit battle between the two was hosted by Mezmo. The two began fighting with their powers and their bare hands, until Mezmo lowered a rack of weapons made from ice for the two fighters to choose from, Skales choosing a katana and a dagger and Slithraa choosing a pick axe and a shield. As the two continued their fight, Mezmo titled the area to alter their footing. Skales eventually won the fight when he used the ancient art of Fang Kwon Do against Slithraa, and he was given the staff and became the new general of the tribe.