Need help with rules for something

So my local GW manager and I are doing a special event on the 31st for the holidays. Somewhat of a tournament but there won't be a tourney winner but you'll get prizes in other ways. So the entire promise is that we have 2 OP termies running around, "Sandy Claws" and Frosty the Snowman, that are going to be rogue termies that kill everything. I am looking for ideas for some rules for them. I have a few already but want some input from others to make them as stupidly broken as possible. For example, "Sandy Claws" can spawn genestealers each turn (I put a genestealer head coming out of his bag of "gifts"), has a 2+/2++, FnP, preferred enemy for everyone on the "naughty list"(anyone that does anything besides run away from him), pair of lightning claws, all stats at 10, and reindeer that give him counterattack and make everyone assaulting him have to take dangerous terrain tests. So, how can we make him more broken? Oh and people get prizes by knocking off wounds. He drops a present for each wound he loses and when you pick it up you roll on a random chart that can do anything from S10 AP1 Large blast on you to a $20 GW gift card or models or nuking the entire board. Frosty is similar though he is kitted out for shooting and has a pretty template for everything that touches him that pins them(no matter what rules they have) and immobilizes them for an extra turn. Any suggestions will be appreciated. We want it to be fun but super hard. Oh and people will be playing games against each other while these to prowl the boards looking for victims.