Video Editing software - object tracking

[Kanpai]

I have a video which I'd like to put my own photos on the animals in a video, what would be the easiest video editing software to allow me to do this?

TIA

 

[AyeAyeAhoy!]

After Effects. You want to track the animal to create a Null Object, then attach your picture to the null.

AE is available for free for 30 days.