I believe that the plot is different.
The plot is different, for sure. I haven't seen Pete's Dragon in so long that I don't remember its plot. I was just comparing that they both featured the main characters: a boy and his dragon-ish friend, and that Pete's Dragon was in an urban setting while Serendipity took place on an island.
Also, Pete's Dragon was live-action while Serendipity was animated...There are quite a lot of differences, actually. I don't recall Pete's Dragon well enough to have much else to say about it.
Sorry for the confusion; my last post probably wasn't worded very clearly.
