is it true that there is a planet or star headed toward earth resulting in a collision?

Anytime you need to ask a question with 'I heard...', you should think twice about where you got your source information from.

We would see a star or planet coming from a long way off and there would be a much bigger commotion if it were happening. Something that size getting anywhere near Earth would be a death sentence for mankind as Earth would probably be pulled due to the gravity out of the habitable zone of the solar system at the least, major earthquakes and volcano eruptions if we were lucky. No, 2012 is the end of the Mayan calender and many nutjobs (forgive the crudity) think knew when human civilization would come to an end and planned there calender accordingly.

There's nothing crashing into earth in the next some years. Due to more recent findings, an asteroid might come close in around 2020, though. but it's no big deal.

No it is not true it does not exist if it was headed for us it would be visible the same thing was predicted in 03 and guess what no planetX.

In a single word, the answer to your question is.....NO! Relax.

nope but look up asteroid apophis... THAT is somthing to worry about

Nope, it's not true.