Bloo is definitely an expressive little blob! He also has the ability to be cute and a pain.
I think one of the main reasons that the is such a pain more so than the beginning of the series is because of his time away from his best friend, Mac.
He might have a fear of Mac outgrowing him or simply forgetting to show up, despite Macs promise. He fears being abandoned like the more than half of the friends at Fosters have been, who may have been the greatest of friends with their creator yet still have been abandoned.
He may be full of himself because he wants to show Mac how great he is so abandonment is not an option.
