Mochi Russia is a sentient mochi creature embodying the nation he represents. He possesses squinting eyes, a prominent nose, and a scarf reminiscent of his human counterpart. Ranked as the second hardest among the mochi, his texture contrasts with softer variants like Mochi Canada or Mochi Italy.

His personality blends playful cruelty with affection. He delights in tormenting others, particularly Mochi America, whom he professes to "love so much that he could tear him apart." After tormenting Mochi America, he flings a heart that brainwashes its target into returning affection, much to Mochi Russia's delight. Despite this rancorous behavior, he also displays a friendly side in certain interactions.

In animated segments, he snuggles into his scarf and sprouts miniature Russian flags from his body. He interacts with other mochi, notably approaching Mochi Italy with cuddling and licking. This behavior visibly distresses Mochi Italy, causing fearful reactions and trembling. Mochi Russia resides in Moscow within the mochi alternate universe and is associated with cold environments, reflecting his nation's climate.

His design and mannerisms remain consistent across appearances, emphasizing his playful yet intimidating nature without significant evolution in character traits or backstory beyond established interactions.