The Carolina Panthers introduced a new main logo, the first change for the franchise since entering the league in 1995.
The differences are subtle at first glance, but the new panther has a more muscular look than the old. The new face has a less cartoonish style than the old. The old may be more aggressive in nature, but the new logo is definitely more intimidating.
Overall, it's a major upgrade without changing the style or color scheme. Sometimes little tweaks go a lot further than going in a completely new direction.
Check out the top most intimidating sports logos of all-time here.