If you're asking what kind of wolves you should breed to be explore wolves, try for heavyweights and heroes, wolves with boosts can be very handy too, especially Crushing Strength and Divine Health.
Try not to get any CP penalty defects, if you want to have a defected wolf in your explore team. They can make it much more difficult to explore.
Pelt defects like albino, melanism, leucism and etc don't come with any CP penalties, so they'll be just as good of an explore/battle wolf as a normal wolf.
Here is a guide to Defects, if that helps. ^^
https://wolfplaygame.com/forums.php?f=29&t=101
Wolves reach their max weight at about 3 years of age, I believe. Then they will stop getting heavier, and you can tell if they are heavyweight or lightweight.
Heavyweight wolves are 130lbs and higher, whole lightweight wolves are 129lbs and lower. The weight of your wolves affects how much damage they do in explore.
If you want to see if a wolf is heavyweight, but they aren't 3 yet, here's a guide on how to do so.
https://wolfplaygame.com/forums.php?f=29&t=119
"Hero" is a term for wolves that have all positive vitals. These are how much extra damage the wolf does in explore during that weather event.
For example, +1 +2 +3 +4 vitals, this wolf is a hero.
0 +1 +2 +3 vitals, this wolf is NOT a hero, they are neutral.
0 +1 +2 -3 vitals, this wolf is also neutral.
-1 -2 -3 -4 vitals, this wolf is a coward, and most likely will not make the best explore wolf.
Winter Month: 2 
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