- "This was your grandfather's. He was one of the Navy's first frogmen during World War II. He was so stealthy in the water, his unit nicknamed him Manta. But after the war, his country forgot about him. So, he went back to the sea, scavenging and surviving with his wit... and this knife. He gave it to me when I was your age. And now it's yours, son."
- ―Jesse Kane to David Kane[src]
The Manta Knife is a special dagger that was owned by Jesse Kane's father and was later passed to him, and later on, to his son, David. After becoming "Black Manta", David stores his grandfather's knife in the side of his suit's right boot.
This special knife was first owned and used by Jesse Kane's father (code-named "Manta" for his stealthiness) during World War II. After the war, however, his country decided to forget about what he'd done during the war; and thus, he returned to the sea and survived by scavenging and using his wits. As stated by Jesse, his father gave it to him "when [he] was [David's] age".
Passing on the Legacy
Following an attack on a submarine by Jesse, David and their crew, whilst father and son were celebrating their victory, Jesse told David that "this [was] [David's] win". Upon presenting this knife to him, David initially scoffed at it, calling it "a piece of junk" and "the love of [Jesse's] life"; however, once Jesse told him that it belonged to his grandfather, and told him the story behind it, David immediately changed his mind about it. He accepted the knife and briefly unsheathed it, revealing the detailed engraving of a manta ray's silhouette on the blade, before putting it away.
- Durability: The knife is made out of an unknown metal, durable enough to pierce Aquaman's flesh.
Behind the Scenes
- As revealed by Yahya Abdul-Mateen II, one of the props used for the Manta Knife was a real knife that could cut someone.