The accident went down Tuesday on a highway near Medellín -- not too far from the late drug lord's massive estate, which has since been turned into a tourist hot spot, complete with a zoo and other attractions ... and from where this animal presumably escaped.

Based on reports, it sounds like the driver was cruising along at night, and ran smack dab into the massive beast. The hippo's dead body was laid out on the street in the aftermath ... it's no easy task to remove an animal that size. Amazingly, the driver was unharmed.

Here's a little history for you to help make sense of this. For starters, hippos are not native to South America, but because Pablo smuggled 4 hippos into the country way back when ... they can actually be found on the continent now, especially in Colombia.

The OG hippos (one male and 3 females) have since died, but their many children and grandchildren live on -- apparently, there are now about 150 hippos in and around that area, all courtesy of Pablo's decision.

With so many of them now in the area, these freak accidents are actually somewhat of a regular occurrence in Colombia. There was another crash in December, and the hippo roadkill is creating a national conversation about what the hell to do with the carcasses.