Maybe my favorite adventure movie of all time is the Ghost in the Darkness. I started wondering how the ACKS would handle that scenario. I looked up Lions and found that their ac is not much greater than a typical encounter. Fine. Their speed and damage looks great. But I find myself wondering how the stealth would work. Clearly they have the speed for hit and run, but how would I handle them sneaking up on the PCs? Anyone want to help me visualize how this would work?
I think of that lion from time to time myself. You’re probably aware that story was based on actual events, and the actual events are at least as spooky as the movie. That lion was no ordinary lion …
For ACKS, I’d invest time in the lion proportional to how long I expected it to appear in my campaign.
For something quick, I’d just give the lion gelatinous cube -level surprise (5 in 6? Don’t have my books …), i.e. Nearly invisible.
For something more, I’d use the L&E rules to boost the lion with ability scores and/or proficiencies.
No. Not an ordinary lion. I thought this would end with me buying that book. :) Thanks for the input.
Thank you for an interesting question 
One other thought. The Ghost in the Darkness is a story from our world, but if the same lion existed in a world of magic and gods, I’d assume those powers might become aware of the lion. This would vary by campaign. For example, the lion might be somehow favored by the god of assassins, with a spell-like ability or a unique power, such as an inability of speak with dead or similar effects to clearly identify a victim’s killer.