TikTok Star Marquay The Goat Cause of Death Revealed

TikTok star Marquay The Goat's died from an enlarged heart ... TMZ has learned.

Sources with direct knowledge tells us the autopsy for Marquay Collins -- the social media personality's real name -- was completed recently ... with the manner of death ruled natural, and the cause due to an enlarged heart.

As we previously reported ... a rep for the the Muscogee County Coroner initially told us Marquay's tragic death was believed to be linked to a serious car accident he was involved in just a few weeks earlier.

Marquay was hospitalized after the crash ... and after returning home, he began complaining of headaches, along with neck, shoulder and spine pain. At the time, the rep for the coroner's office told us Marquay also mentioned to his brother that he was experiencing shortness of breath and headaches.

But clearly ... the investigation ultimately pointed in a different direction.

Marquay built a massive following ... racking up 7.1 million followers on TikTok and another 501K on Instagram -- known for posting about food reviews and fast cars

He was only 24.