"You Baxters has got guts, I'll say that" (15.168)
In a basically cashless economy (seriously, they trade a dog for a gun), you can't impress people with your flashy car or sweet new kicks. But you can impress people with your courage.
"Jody longed to talk of it, to cast away the spell of the tracking, and the fight, and the fear that had struck him" (4.112)
Jody would haven't called this talk therapy, but that's the general idea: he wants to talk through his fear. It may not sound like courage, but it's the first step to getting back out in the forest.
"He turned abruptly and began to push through the scrub in the direction of the clearing" (14.74)
Sometimes, courage isn't about how you feel or what you say: it's about what you do. We have no idea how Penny feels when the rattlesnake bites him, but we know how he acts—decisively and bravely.
"His fear had a name, and was no longer quite so terrible" (14.136)
Weirdly, once Jody realizes that Penny might die, he's no longer so afraid. It's kind of like learning that you're going to be delayed on the tarmac for another hour: at least you know how long it's going to last.
"Penny made a rush at the alligator" (20.169)
Two words: alligator wrestling. Okay, okay, a few more words. This is really brave of Penny, but we have to ask: at what point does bravery become stupidity?
"He handed Jody his gun and retrieved his own from the side of the fence. He leaned and picked up a hoof of the calf and walked decisively toward the house, dragging the carcass. … [Jody] was still frightened. A panther or a bear at bay always terrified him" (23.38)
There's nothing more dangerous than a trapped animal, especially a trapped predator. (Always shoot to kill, Shmoopers.) That's why Penny's courage is so impressive—especially in contrast to Jody immature (but totally understandable) fear.
"Now I was scairt," he said. "My very bottom's cold" (23.54)
Penny only gets scared when he's up against something he can't handle alone, like the wolves. There's nothing like a big group of Forresters to buck up a man's spirit.
"He was not afraid, he told himself, but his mother might be" (23.61)
Sometimes, all it takes to be brave is knowing that someone else is frightened. After all, if your roommate isn't going to get rid of the cockroach, someone has to. Here, Jody manages to use Ma's fear to make himself feel just a little better.