Assassin's Creed Mirage

There is a snake on a rooftop in Yasiriyah protecting a chest

https://ibb.co/BgL0mmp

I just sat on a wall and waited for 10 minutes

https://ibb.co/x261B3T

Attack a group of guards and kill all but one. Then dodge all incoming attacks from this enemy, do this for 10 minutes.

Just a fun little fact: this is a throwback to the 2007 achievement Eagle's Flight from Assassin's Creed, which was basically the same achievement.

The above solutions where you should go to the wilderness and find a snake are simple and straightforward, but if you are still at the beginning of the game and don't have any viewpoints there and you feel it will be a long road for you to get there, you can try blocking enemy attacks till you pass 10 minutes.

First use your Eagle vision and find an enemy guarding a chest inside a room of a building, get inside and start fighting him, if there's another guy kill him and leave only one, simply keep blocking his attacks by LB when he uses light attacks to deflect and stun him, and use X to evade his heavy attacks when he turns to red, keep some elixirs in your inventory to heal yourself in case you got hit, but you should be fine as long as you deflecting in time which is so easy to implement in this game. After 10 minutes of blocking the achievement should pop for you.

Good spot that doesn't require you go out of your way as part of the main quest. During the quest Like Father, Like Son, a character will ask you to pick flowers from a patch of high grass. There are a couple snakes in the grass when you approach the objective. Jump on the fence post next to the snakes (there is a unlit torch next to it) and wait ten minutes on there. The snakes will still be aggroed to you, but they can't reach you.

I did this while exploring. If you head towards the southern part of the map to the little town Jarjaraya (there is a viewpoint) and head south to the Spymaster’s Camp, you’ll encounter 3 leopards. There was a branch (heads to the tree house with chest) that I got on where the leopard could not get me. I waited the ten minutes and the achievement popped. I hope this is helpful. Happy achievement hunting.

The top guide is definitely great, but I found a fun way to do this very early on. Go to the Damascus Gate Prison. To the left, there is a long strip of land that runs the length of the prison. Trigger some guards, get down to that strip of land, and like the days of COD: Zombies, run them in a circle! I personally had about a dozen guards chasing me, but as long as you keep your distance, it will be an easy 10 minutes. Happy hunting!