Before Crisis: Final Fantasy VII
Voice Actor: N/A
Deneh is a resident of Cosmo Canyon alongside Red XIII (Nanaki) and they are also of the same species. Together with Nanaki, Deneh was supposed to perform the rite to appease the planet, but Nanaki was extremely hesitant.
It is during this time that Deneh is actually attacked by people - believed to be the Turks - and she is fighting a losing battle. Realising this, she runs away and is spotted by Nanaki.
Allowing Nanaki To Become A True Warrior
Seeing Deneh in trouble is the key to unlocking Nanaki's emotions, as he realises the true meaning behind his thoughts. Deneh is rescued by Nanaki, who fights off the Turks.
After this, it is presumed that Deneh passed away, as she is not mentioned in Final Fantasy VII when Hojo claims that Nanaki is the last of his species alive. However, given that Nanaki appears with some cubs at the end of Final Fantasy VII and the start of Advent Children, they could have mated before she hypothetically died. Or, she is still alive, but is never seen or mentioned.