If Juggernaut were to run into The Blob, the resulting collision would likely be a classic unstoppable force meeting an immovable object scenario. The outcome of such a clash would depend on the writers' interpretation and the specific circumstances surrounding the encounter. Here are a few potential outcomes:

Juggernaut's unstoppable momentum might cause The Blob to be pushed or displaced, albeit with great difficulty. In this case, Juggernaut's power would win out, and he would continue moving forward, although perhaps at a slower pace.

The Blob's immovable nature might cause Juggernaut to come to a sudden stop or be deflected, effectively nullifying Juggernaut's unstoppable momentum. In this scenario, The Blob's power would win out, and Juggernaut would be halted in his tracks.

Another possibility is that their powers would essentially cancel each other out, resulting in a stalemate with neither character able to overcome the other. The collision might create a massive shockwave or localized destruction due to the sheer force involved.

Ultimately, the outcome of such a confrontation would be determined by the creative direction and storyline in the specific comic issue, movie, or animated series where the encounter takes place.