Generally, when your mascot is a bird, it allows for a lot of cool design options. That is especially true when compared to something like a… squirrel. Luckily, there are no squirrel mascots in football yet. That could all change when the Chiefs are finally forced to change their name. These Falcons helmets make great use of the falcon mascot.
The top right design is very striking with its use of the wings. The color scheme for the wings makes them pop. Then the simple design of the bottom left is a great choice as well. There is no mistaking which team would be wearing those helmets, which is a big consideration to make when designing a helmet. You want fans to be able to spot the team right away, without having to second guess.