170,000-Year-Old Cicada Adult

170,000-Year Magicicada Adult (17万年ゼミ成虫, Jūnana Man-nen Zemi Seichū) was a large Mysterious Being that attacked Z-City at some point during Saitama's training years.

Appearance
The Magicicada Adult was an extremely massive cicada-like creature, easily able to cast a large shadow over a city. Located at the center of its head was the face of a man.

Summer
170,000-Year Magicicada Adult attacks Z-City damaging many buildings. Saitama then appears before it and declares with a smile that summer has arrived.

Abilities and Powers
Since it is the grown up version of the 170,000-Year Magicicada Nymph, it is presumably much more powerful. Even S class would have difficulty dealing against it due to its resistant shell and its ability to fly.

Flight: His wings allowed the Magicicada Adult to fly.