Finally got to look at the actual monster creation guidelines in the DMG and frankly most of the monsters out there aren’t created as intended although they’re cool. But strictly by the book they’re all a little OP’d I believe having additional powers that by the book or RAW they probably shouldn’t have. Doesn’t make them useless, just something to be aware of if you’re going to use them.
If you’re creating your own monsters then this stat generator might come in handy and he has a statblock program as well although I’m not 100% thrilled with it as the formatting is ‘off’ in some places and requires hand editing of the html to get it to match the ‘official’ formating. That doesn’t break anything of course, the monsters are still just as deadly or not as the case may be. 
