In Warframe, you will need Medjay Predasite Tags to rank up with the Entrati Syndicate. To get them, you will need to engage in some animal conservation on the Cambion Drift on Deimos.
What you need
You are going to need some very specific items for a chance at catching a Medjay Predasite. First up you will need a Tranq Rifle that you can purchase from Son in the Necralisk if you do not already have one. It will cost you 500 Standing. You will also need to purchase a Predasite Echo Lure from Son for 1000 Standing, and finally you will need some Predasite Pheromone Gland. These single use items cost 150 Standing, and will increase the rarity of the Predasite that shows up when you are tracking them.
How to capture a Medjay Predasite
Head out to the Cambion Drift, and get out your Tranq Rifle. Switch to the Predasite Echo Lure so that only those sites will appear on the map, then travel to one of them. When you get there, find the animal poop and interact with it, then follow the trail. Predasite trails are quite easy to follow, just don’t step in the toxic poop.
When you get to the nest, use the Predasite Pheremone Gland before you use the Echo Lure. This will increase the chances of a Medjay Predasite spawning. Use the Echo Lure, then repeat the Predasite’s call and switch back to the Tranq Rifle. When the animal shows up, hit is twice with the Tranq Rifle. If you are lucky, a Medjay will appear, if not you will need to rinse and repeat until you get one.
Don’t forget, Warframes with invisibility make animal captures much easier, as the animal won’t know you are there.