Clunky, Shaking sounds from under the hood + smoking muffler

Hi everyone,

Once I start the car, the engine area makes a clunking sound and shakes pretty hard. It also happens when we accelerate on the gas at the beginning. We also have smoke coming out of the muffler and the are smells with a burning of sorts smell. Yesterday, I ended up driving after it was doing this and nothing happened during the 10 minute drive. It happened again last night so we did not drive it again and have not since.

Any idea of what might be happening in this case?

I have videos showing what is happening, but can't upload as a .mov or .mp4. Figuring out what file format this forum takes.

thanks,
Jef