Trident is a mysterious object found by Zac Blakely. It looks similar to Poseidon's Trident from Greek mythplogy and it can control lightning, drain the life force of mermaids, detect Invisibility, and possibly can do more in control of the merman who finds it most. In "Zac Returns to Mako", Zac takes a portal from Trident Cave into the ocean which has the Trident in it, but he leaves before he can grab it. In "Betrayal", Zac takes a portal from Trident Cave into the ocean and grabs it, but Lyla tries to take it away from him. When mermaids touch it, it sparks out of control and kicks everyone out of the portal. Zac was under the influence of the Full Moon and when he touched the Trident he snapped out of it.
In "I Don't Believe in Mermaids", Rita Santos reveals that a pod of mermen took the Trident into battle and the mermaid pods had to draw upon the power of the oceans to defeat them. The Trident was locked away to prevent a similar situation from happening.
- the trident is the most dangerous weapon it can destroy all the mermaids even the pod which explains why it's dangerous for Zac and Erik to use in unnecessary conditions.
- Weilan had a pod and her pod got destroyed by the water dragon she is really upset when Weilan went to Rita, the water dragon followed her the water dragon wanted to destroy the sudden mermaids, Weilan didn’t know the water dragon was following her.
- It's been believed that mermaids shouldn't use their 50 moon rings under any circumstances, because it won’t help Evie ever get her tail back.
- The trident's stone lights up when a mermaid is close to it.
- It is hidden by Lyla in a "place that Zac will never find it" .
- Cam destroys the trident when he's seen dangling down from the moon pool.