Ah, friendly? Some are, but most wild Pokemon can be skittish, or even aggressive. Dragon-types found in the wild are exceptionally difficult to train; they tend to not work alongside humans very easily.

[ you wouldn't know it, looking at dragonite, who seems to be perfectly friendly and calm, amongst all of these people. he is a good boy. ]

He can also understand you; Pokemon are sapient.

[ dragonite can understand language and respond to it in kind, and communicate in his own way. ]