SMITE

Ice Isn't Nice
As Skadi catch 3 or more enemy gods on Permafrost.

What you have to do is get into a team fight, and use the ability Permafrost, which is a medium size circle, in a crowded area. The best gamemode to do this on is Arena because it is largely team fights. This isn't an achievement that you need to really be aware of to get because if you are playing her correctly you will use this as a stun to help your team secure a couple kills.

I was able to get this on the first game I played with her. The hardest part is knowing what you actually need to do.

As this is a Skadi only ability, first you need to get her (buy permanently, rent, get through ultimate god pack). Now enter any match type, as mentioned by Awesomesax555 Arena is the way to go and is by far the easiest game type to do this in. One thing that I would like to add in addition to his solution is that Permafrost stays around for a good 10-15 seconds (give or take. It may have lasted longer but I wasn't really paying attention to really count) and therefore you don't need to catch them when immediately casting it, but so long as they walk into it while it's active it counts. This is what happened to me, I caught two immediately during casting and a third walked into it while active and while my back was turned and the achievement and in-game award unlocked.