This version of Puppy can be downloaded from Softpedia
Precise Puppy 5.4, a distribution built from Ubuntu Precise Pangolin 12.04.1, alongside the binary DEB packages, providing full compatibility with Ubuntu and access to the vast Ubuntu package repository, has been released.Precise Puppy 5.4 is the first distribution in the series built on Ubuntu Precise Pangolin 12.04.1. The version number has been allocated so it reflects its position relative to the other puppies, such as Wary 5.3 and Slacko 5.3.3 (5.4 coming soon).
Quite a few modifications have been made, at the "Woof-level" since the release of Wary 5.3 back in April 2012. More precisely, this version has a lot of enhancements for the Puppy Package Manager (PPM).
Ubuntu 12.04 Precise Pangolin is a 5-year long-term supported release, therefore Precise Puppy will be also supported for the amount of time.
Download Precise Puppy 5.4 right now from Softpedia.