Beasts is a general name for the wildlife in Path of Exile Wraeclast. These include all the animals listed and classified in the Bestiary. With the help of Einhar Frey, these beasts can be hunted and captured and brought to the Menagerie before being sacrificed.
Resurrected or undead versions of beasts (e.g. Bone Rhoas) do not count as beasts, and therefore cannot be captured. The following are the short tips for collectors of poe currency trade on how to capturing beasts:
1. In order to throw a net you must have your mouse over a trappable monster.
2. If they are above 25% hp there is a high chance it will fail.
3. If the net fails they are enraged for a short time and cannot be trapped.
4. If you net a white mob even if it fails they will be teleported away and Einhir will say you captured a beast - bug.
5. As you reach the top 1/3 of the nets level range it fails far more. Also note that rares and uniques are 2 levels higher than the zone you are in.
6. There is a recipe for Adrenaline Quicksilvers. 1x The Faun (In The Climb where you get Navali) 3x Any goatman.
Hopefully the above guide will be helpful to you. If you do not want to lag behind others due to lack of orbs, you can keep an eye on some poe items for trade.