I think this question is less of a "can I make the antagonist a good guy" question and more of a "is it a good strategy to make the antagonist a good guy turned bad" question. The example you cited with Tigerclaw would follow, since I would argue that he's not a good guy by regular means. (I've read the Warriors books!)
Is this a good writing strategy? Sure, if it fits your plot. I don't see the issue with it.
How could you make the antagonist appear to be a good guy to the reader? Well, by all means, just write them like a good guy. The point is that the reader doesn't know that your antagonist is one of the good guys. So if you write them like a good guy, the reader is unlikely to suspect anything -- unless, of course, you give hints at the antagonist's true nature.
I would say it varies a little. If your antagonist was a bad guy from the start and is only masquerading as a good guy, you might write them differently than a good guy who turned into the antagonist by becoming the bad guy. The "fake good guy" antagonist has evil plans from the beginning; you may consider dropping clues to their real identity, or you might write them as a good guy through and through until you decide to reveal them.
The "good guy turned bad" antagonist is a little trickier, I think. This is because something changed them and made them become the antagonist (unlike the "fake good guy" antagonist, who was just lying the whole time). The "good guy turned bad" antagonist generally goes through something serious, and as a result their character is changed. Maybe they became the antagonist because the main character got together with the person they liked, and they got jealous and plotted to murder the main character. Maybe they became the antagonist because their entire family died in a horrific car accident, and now he's frustrated with everything and goes mad.
Lastly, I'd like to mention that "good guys" and "bad guys" are relative. Every single person that's ever existed is simultaneously a good guy and a bad guy; the same goes to characters. Your antagonist may be a "bad guy" by regular standards, but to someone, they're a good guy. And that, I would argue, is how you should write your antagonist. Because not every antagonist believes they're doing evil. Many do "evil" things with the honest intention of making the world a better place.
Write your antagonist like a good guy, whether or not you're trying to make your reader think they're a good guy. Your antagonist most likely thinks they're a good guy too. ;)