Noah's Cradle

However, its name has been passed down amongst the thousands sent into
space on a ship for the purpose of avoiding the extinction of the human
race. Liking this to the one from the legend of the Great Flood that
destroyed Earth, people began referring to this ship as "Noah's Cradle".

One such Cradle struggled along until it reached a large gas planet.
Confirmed within the planet's atmosphere were gigantic creatures that
ranged from between an estimated several hundred to several thousand
kilometers in length. The harsh atmosphere wasn't the only thing that
stood in the Cradle's way as it descended into the atmosphere. The
Cradle was under attack.

Thus, the battle began.