Okay, so I've got my 5 mill out and I'm ready to buy this thing because.. It WILL get me the avatar(s), right..? And once I get the trap.. What do I do? I'm only being very cautious because it's not everyday I waste 1/6th of my total sP.. =P

You just leave it in your inventory and wait for lizard events.

Oh! It's that easy? Geeze, I'm crazy. =P I thought there was a lot more too it. Well, thank you. =)

I would get the lizard minion spray in addition to the trap, as well.

It's only 1m more. That super rare item the lizards decide to leave you will be much appreciated when they finally come. :)

I'm fairly sure this is not neopets. :X

Maybe after she gets the comatose lizard achievement, since you can't get that one if you have both the trap and spray.

You don't have to do anything except have it in your inventory (and wait for a Lizard Random Event) to get the achievement, however, you do want to make sure you put the trap (and spray, if you buy it too) into your vault before you go zapping any pets - the V2 has a tendency to go after items, and you wouldn't want your trap to turn to dust!

Whatever the choice, you cannot get the achievement unless you have at least one or the other in your inventory. Good luck in getting it. :)

1. There used to be avatars here.
2. You're still right. They're called achievements.

Pedantry aside: By just keeping the trap in your inventory you get the comatose lizard one. If you have the spray you won't be able to get the comatose lizard. So put off on the spray until you get the lizard. :) (And you might get lucky and get both with just the trap!)

I think the lizard thing is random.

I believe there's a 50% chance of the trap working, and a 25% chance of the spray working. Also, only the trap can capture a comatose lizard.