MacOS 10.16

macOS 10.16 was a version of the macOS operating system that had been anticipated to succeed macOS Catalina (version 10.15). However, macOS Big Sur was instead announced as version 11 on June 22 at the 2020 Worldwide Developers Conference and released on November 12, 2020.

Preliminary revelation at WWDC 2019
During a presentation of SwiftUI and RealityKit at the 2019 Worldwide Developers Conference, Apple engineering director Josh Shaffer jokingly "leaked" several working titles of macOS 10.16 supposedly being considered at random by Apple's "crack marketing team":
 * macOS Avocado
 * macOS Baby Deer
 * macOS Bunny
 * macOS Capybara
 * macOS Colorado
 * macOS Flying Squirrel
 * macOS Goat Rock
 * macOS Oxnard
 * macOS Sea Otter
 * macOS Tiger (Already Taken)