Trolls aren't hard to identify. They're grey and black and have horns. I imagine they'd look something like this, in the event that they would for some crazy reason become lions and not prepubescent aliens:
Usually they have larger horns though. This guy just has little ones. Aww.
(Okay wow that was bad and I feel bad.)
...all joking aside, I find the best way to deal with trolls is to react in a way that they don't expect. If they start trolling you, you should just be all, "yeah bro that's cool" or roll with it and act like you are interested deeply in their conversation. Eventually they tend to either get bored because you aren't reacting as they wanted you to, or they will revert out of troll mode and actually talk to you. I tend to have very little problem with trolls this way. I don't recommend trying to get them to talk about something you like, just keep talking to them about whatever they're talking about - for example, if they go, "Hahaha trololol i pour peanut butter all over your feet" you can just be like, "Thanks man, I needed some peanut butter to make a sandwich!
" the friendly attitude tends to disarm them because they expected you to be grossed out or be angry or try to tell them off.
Anyways that was my two cents. <3
