Doriru-Mogura is a mechanical synthetic monster from the 1973 series, appearing in the television episodes and the theatrical film Kamen Rider V3 tai Destron Kaijin. This creature was originally a human man named Kuroda Yuji, a stalker who harbored an obsessive infatuation for the young woman Tama Junko. Consumed by jealousy and resentment toward Junko's associate, Kazami Shiro (the alter ego of Kamen Rider V3), Kuroda was targeted by the evil organization Destron. After witnessing Kazami transform into V3 during a battle, Kuroda was captured and subjected to surgical modification by the evil scientist Dr. Inugami, resulting in his rebirth as the mole-themed monster Doriru-Mogura.

The personality of Doriru-Mogura is a direct, monstrous extension of Kuroda's human flaws. He is cunning and underhanded, preferring to rely on trickery and psychological manipulation rather than engaging in a straightforward fight. His driving motivation is a twisted, selfish desire to claim Junko as his bride. To achieve this, he follows the order of the Destron leader: he must first eliminate Kazami Shiro. This goal is pursued with a notable lack of honor, as he habitually resorts to schemes that put innocent people in danger to achieve his objectives.

In the story, Doriru-Mogura serves as a direct personal antagonist to Kamen Rider V3, created specifically to exploit the hero's human relationships. He escalates his stalking by kidnapping Junko and holding her captive in a Destron hideout. His primary role is to force a confrontation on his own treacherous terms. He lures Kazami into a trap by using Junko's younger brother, Shigeru Tama, and members of the Junior Kamen Rider Squad as hostages. He demands that Kazami come alone to a pine grove, where he sets a particularly cruel trap: a bomb disguised in the likeness of Junko herself, hoping to destroy V3 through deceit. His key relationships are defined entirely by his obsession, with Junko as his desired prize, V3 as his hated obstacle, and Destron as the power he uses to pursue his selfish whims.

Doriru-Mogura does not undergo significant personal development, as he is a single-minded villain. However, his tactical desperation becomes evident during his final battle. When his bomb scheme fails and V3 survives to crash his forced wedding ceremony, Doriru-Mogura finds himself outmatched in direct combat. True to his nature, he attempts to flee by burrowing into the ground, but this escape is blocked. His story concludes with his destruction, as he is obliterated by the V3 Reversal Kick. In the theatrical film, a regenerated version of Doriru-Mogura appears as one of many revived monsters, serving as an obstacle for the hero without the original character's personal vendetta.

In terms of abilities, Doriru-Mogura is defined by the massive drill mounted on his head, which is powerful enough to pierce ten meters of concrete in an instant. This drill is his primary tool for both combat and mobility, allowing him to burrow through the earth at high speed and ambush his enemies or create tunnels for escape. He uses this burrowing ability offensively to cause cave-ins and bury foes under massive amounts of dirt and sand, aiming to suffocate them. He also possesses sharp claws on his hands, which serve as secondary weapons. Despite these formidable powers, Doriru-Mogura has clear weaknesses: he is slow and clumsy in his movements, leaving a critical opening when he must pull his drill out of a target after piercing it, and he is notably ineffective in or under water.