The client envisioned a Leviathan, from Trinity Continuum: Aeon, reimagined with inspiration from a Lionfish instead of the planiform depiction as illustrated in the sourcebook, for the game they're running.
Leviathans, as described in the sourcebook, are "the largest vessels ever made by humans, and employ both biotech and hardtech (this just means traditional technology) in a unique combination. Multiple hyperfusion reactors propel the Leviathans through space in normal flight. Advanced biotech life-support and accommodation systems provide a thriving and surprisingly naturalistic biosphere capable of supporting up to several thousand passengers and crew."
And according to the client: "the Mabuhay was commissioned by the United Nations in 2120 to reestablish contact with lost colonies, make contact with alien civilizations, and generally explore the galaxy after a period where humanity was cut off from the stars without access to FTL travel or communications."