michaelispolly
Junior Member
Have no luck in catching one, either they don't appear or the attacked me every time. Any tips? 

I'd recommend not equipping your net until you see one. Move carefully while searching for one, don't run at all. When you do find one, equip your net and sneak up on it from behind. If it notices you and makes a hissing noise, don't move. Wait until it turns away from you then sneak up on it again.
In addition, this video is a good demonstration:
When it hisses at you, you can just keep slowly sneaking up to it and it will just keep sitting there and hissing. Once you get close enough, just release A and you've got it.