When Jack Kirby, among the greatest comic book artists ever, first conceived of the Black Panther character before his debut in Fantastic Four #52, he named him Coal Tiger. The name later emerged with T'Chaka II, the son of Black Panther in the MC2 alternate universe. He physically transforms from a human into a super-strong human-panther hybrid.
The Black Panther from the Marvel Mangaverse owes his powers to the Egyptian god Horus, making him extremely powerful. In addition to the basic abilities to be very fast and strong, he can also transform himself into a humanoid panther. The Earth-2301 version of the character can also summon spirits to inhabit his body, gaining all of their power and knowledge.
His Hellfire manipulation and supernatural awareness instantly rank among the most powerful magical beings in Marvel Comics. Instead of a motorcycle, Ghost Panther rides a flaming black panther, and he can travel between dimensions on it.
In Marvel's Mangaverse designated as Earth-2301, T'Challa is able to transform into a Were-panther. In Marvel Mangaverse Issue #4, when Doctor Doom attacks the UN summit, T'Challa is shown to transform into a were-panther (image below). However, this is supposed to be his normal ability (as opposed to the other Marvel universes where he wears a suit).
Considering you'd also like some other instances, King T'Chaka was also able to transform into a Were-Panther. In the animated movie Ultimate Avengers, when Herr Kleiser attacked Wakanda with his Chitauri army, the Black Panther's mantle was still with T'Chaka. He tried to defend his kingdom but was ultimately killed in the process. However, during this time, we do see T'Chaka transform into a were-panther (watch the video below; transformation at the 3:00 mark)