Safari Net

The Safari Net (Reusable) is used to capture any mob for carrying in your inventory, and later placing elsewhere, similar to spawn eggs. If the mob you intend to capture has a right-click action (like villagers) you must Shift+Right to capture the mob, alternatively you can use the Safari Net Launcher. Once a mob is captured in it, you can use the Safari Net (Reusable) in an Auto-Spawner to produce copies of the captured mob.

These are also sold by the zoologist villager.

2 obsidian blocks

Bugs

 * Capturing an Enderdragon may cause your game to crash.
 * Capturing an Iron Golem may not allow you to release it, rendering your net useless.