TV-Series
Description
Myōga, a flea demon retainer to the powerful dog demon Tōga, urgently warned his master about unhealed wounds after Tōga's battle with Ryūkotsusei. Despite Myōga's concerns, Tōga dismissed them to protect the human Izayoi. After Tōga's death, Myōga helped seal the sword Sō'unga within the Bone-Eater's Well alongside Tōtōsai and the sheath spirit Saya for 700 years. Assigned to guard Tessaiga's hiding place in Tōga's tomb, Myōga fled when Sesshōmaru arrived seeking the sword. He located the newly freed Inuyasha, reaching Kaede's village. During Sesshōmaru's attack using a Mu-on'na, Myōga aided Kagome by sucking her blood to break chains and explained the Mu-on'na's nature to free Inuyasha. He then urged Inuyasha and Kagome to pursue Sesshōmaru through the Black Pearl portal into the Border of the Afterlife, revealing Sesshōmaru's intent to claim the sword embedded in their father's bones. Myōga consistently evaded physical threats, fleeing during Sesshōmaru's transformation and Inuyasha's battle against the unsealed Ryūkotsusei after Naraku melted the sealing claw.

Frequently traveling independently to gather intelligence, Myōga reappeared unexpectedly with crucial information. When Tessaiga broke against Naraku's incarnation Goshinki, he identified its role in suppressing Inuyasha's demonic transformation during near-death experiences and advised against informing Inuyasha. He later guided Inuyasha to Ryūkotsusei's valley to absorb power from Tōga's claw, though Naraku's interference released the demon. Myōga also provided knowledge on strengthening Tessaiga to penetrate Naraku's barrier, directing Inuyasha to bat demon Taigokumaru's island for blood empowerment.

During the Band of Seven crisis, Myōga discovered Kagome, Miroku, and Sango poisoned in a burning temple. He revived Shippō through bloodsucking and cured the trio by extracting toxins, preparing antidotes from poisonous snakes. Despite their gratitude, he fled afterward, fearing the Shichinintai.

In the final Shikon Jewel shard quest, Myōga initially doubted its presence in the Border of the Afterlife but escorted Inuyasha's group to Hōsenki, creator of the Black Pearl. Learning of Hōsenki's death, he warned against entering the Realm of Fire yet accompanied them, cautioning about guardians of the Gate of the Afterlife. When Naraku corrupted Hōsenki via the shard, Myōga recognized him and vouched for Inuyasha's intentions before advising retreat upon Naraku's appearance.

Later, assisting Inuyasha's daughter Moroha and her cousins, Myōga identified Tōkotsu as one of Kirinmaru's Four Perils during Jakotsumaru's resurrection attempt. He explained Taigokumaru's blood properties when Moroha sought to strengthen her techniques and escorted the group to swordsmith Yakurōdokusen to restore Sango's damaged Hiraikotsu. During this mission, he encountered Tōga's old enemy Shishinki and witnessed Sesshōmaru learning Tenseiga's origins as a Tessaiga fragment.