What is the heaviest pantera song?

The heaviest Pantera song is "Becoming". It is a song from their 1992 album "Vulgar Display of Power" and is known for its extremely heavy and aggressive sound. The song is driven by a fast and pummeling drum beat, heavy and dissonant guitar riffs, and aggressive vocals from Phil Anselmo. The lyrics of the song also emphasize its heaviness, with Anselmo singing about "becoming the beast" and "conquering all."