They were originally a Lion. Not a mountain lion.
No, it was intended to be a Mountain Lion, but whoever made that first costume didn't know the difference between a Mountain Lion and African Lion. And it brought bad luck
"At the time, Penn State did not have a mascot, save for the unofficial “
Old Coaly.” Thinking quickly on his feet in an attempt to intimidate the opposition, Penn State third-baseman
Harrison “Joe” Mason responded, “Well, up at Penn State we have Mount Nittany right on our campus, where rules the Nittany Mountain Lion, who has never been beaten in a fair fight. So, Princeton Tiger, look out!”
In the years that followed, Mason was reminded of his quick-witted response and the ongoing absence of an official school mascot each time he passed through campus. On display in Old Main was the stuffed and mounted remains of what, according to legend, may have been one of the last Pennsylvania mountain lions. The animal was shot and killed in nearby Susquehanna County in 1856, by a man named Samuel Brush. Though once a common predator in the commonwealth, mountain lion numbers were rapidly dwindling throughout Pennsylvania by the mid-1800s.
For 18 years after first appearing on the cover of LaVie, the Nittany Lion more closely resembled an African lion than the mountain lion Mason had envisioned. In the fall of 1921, for the first time, a student donned a costume — complete with a mane — and crawled on all fours during a football game. Richard Hoffman, Class of 1923, was chosen as the first student to serve as the mascot after he portrayed the king of beasts in a campus theater production of "Androcles and the Lion." Following Hoffman's graduation, the Nittany Lion went dormant for four years, until Leon DeRoy Skinner, who was six feet tall and could fit into the suit, was asked to resurrect it. Skinner had taken the field at four games that season — all which resulted in losses — when an apparently superstitious Coach Hugo Bezdek ordered the mascot to be banned from the field.
“... and that was the end of the Nittany Lion, African-style,” said Skinner at the time.
The Penn State mascot would not appear again for 12 years, making its comeback in 1939. That fall, The Daily Collegian began to solicit money to pay for a new lion suit, which took on a look more closely resembling the Nittany Lion we know and love today.