← Back to General Guides

Glacieradon Guide — Zombie Invasion Alliance Boss

Alliance · 2026-10-14

What Is Glacieradon?

Glacieradon is the alliance boss that sits on top of the Zombie Invasion event. When it is active the event is named Zombie Invasion - Glacieradon in the event list, and the usual zombie-farming event gains a second layer: your alliance can summon and kill a giant ice beast for a separate set of rewards.

It is not an extra event with its own schedule. It is part of Zombie Invasion, and it only appears in the runs where the beast is included.

One Challenge, One Button, One Hour

Each alliance gets exactly one Glacieradon challenge per event, it has to be started by hand, and only the leader or an R4 can start it. This is the single biggest reason alliances get nothing from it. The bar fills, nobody presses the button, and the beast leaves. Decide in advance who starts it and when.

When It Appears

The season panel lists the unlock as Tempest Beast on day 57, with the note that it awakens Glacieradon. From that point it is part of the game's recurring event rotation rather than a one-off piece of season content — which is why it also turns up between seasons.

Do not confuse it with two things that share the name:

Zombie SiegeA completely separate alliance event. Waves of zombies attack every member's base. Nothing to do with Glacieradon
Season 2 Nuclear FurnaceThe Season 2 warzone event also features Glacieradons — four of them, marching across the map at the Nuclear Furnace. Same creature, different event, different rules

How the Challenge Is Unlocked

The gate is Zombie Bosses, not zombies.

  1. Kill invading zombies on the world map. These pay Courage Medals, which you spend in the event shop. They do not fill the Glacieradon bar.
  2. Zombie Bosses have a small chance to appear after a zombie kill. They are strong enough to need a rally.
  3. Defeating Zombie Bosses earns Glacieradon progress points for your alliance. This is the only thing that fills the bar.
  4. Once the bar is full, the leader or an R4 triggers the challenge manually.

So the alliance's job in the first half of the event is to find and rally Zombie Bosses, not to grind ordinary zombies. Players farming zombies flat out for Courage Medals are earning for themselves and contributing nothing towards the beast.

The Fight

Once an officer starts the challenge, Glacieradon spawns and a clock starts.

RuleDetail
Challenge length60 minutes. If its HP is not at 0 when the hour is up, it escapes
Attacks per player30, for the whole event — not 30 per day and not 30 per challenge
CritsAny successful attack can crit for several times its normal damage. Crit attacks also pay multiplied rewards
Ice attacksGlacieradon freezes commander bases. A frozen base cannot relocate or rally until it thaws
Other alliancesYou cannot attack Glacieradon while another alliance is challenging it

The freeze is the mechanic people get caught by

Rallying is how most alliances handle every other boss in the game. Glacieradon's ice attack takes exactly that away — a frozen base can neither rally nor relocate. Plan around members dropping out of the rotation mid-fight rather than assuming everyone can act for the full hour.

The Clock That Actually Matters

Glacieradon Leaves Two Hours Early

Glacieradon departs 2 hours before the event ends, and no challenge can be started after that. The deadline for starting is not the end of the event — it is two hours before it. An alliance that plans to "do it on the last evening" can find the button already dead.

Work backwards from that. The challenge takes an hour, so the last useful start is three hours before the event ends, and even that assumes a full turnout. Pick a slot when most of the alliance is awake and online, and announce it.

Rewards

  • Every successful attack pays an attack reward, and a crit multiplies it.
  • The final blow pays 10x. If the killing blow is itself a x2 crit, it pays 12x — the multiplier is applied on top of the crit rather than instead of it.
  • Glacieradon's Treasure drops when it dies. Collect it from the map for a large reward.
  • Kill it and every alliance member gets a reward mail. Fail and everyone still gets a participation reward. Each player collects that mail once per event.

Nobody is punished for taking part, so there is no reason to hold attacks back. The only thing a saved attack does is make the kill less likely.

Two reward rules worth knowing

24-hour join ruleNew alliance members cannot collect Glacieradon's Treasure within 24 hours of joining. Recruit ahead of the event, not on the day
Other alliances' treasureYou cannot claim the treasure dropped by another alliance's Glacieradon

If that 24-hour rule sounds familiar, it is the same family of trap as the 48-hour rule in the Zombie Siege guide — joining an alliance the day of an event routinely costs the new member the rewards they joined for.

What We Have Not Confirmed

Glacieradon's HP is shown on the challenge screen and drops as the alliance lands hits, with crits taking several times as much off at once. We have not confirmed the HP scale or the crit rate, so we are deliberately not publishing a "you need N players" number — a wrong one would have alliances starting a challenge they cannot finish, which costs them their single attempt.

If you read the HP figure off the challenge screen, send it in and we will add the maths here.

Likewise, the number of progress points needed to summon it, and how many points each Zombie Boss level pays, are not stated anywhere a player can see. The panel says only that enough points must be gathered.

Officer Checklist

  1. Before the event — recruit, so new members clear the 24-hour treasure rule.
  2. Early in the event — push the alliance onto Zombie Bosses, with rallies, not solo zombie farming.
  3. Pick the start slot — peak online hours, announced, and at least three hours before the event ends.
  4. Start it yourself — leader or R4 only, and the alliance gets one attempt.
  5. During the hour — everyone spends attacks. There is no reason to save them.

Common Mistakes

  • Waiting for the bar to start it. It never does. The challenge is manual.
  • Leaving it to the final hours. The beast leaves 2 hours before the event ends.
  • Farming zombies instead of Zombie Bosses. Medals are yours; only bosses fill the alliance bar.
  • Saving attacks. There is no second challenge to save them for.
  • Recruiting on the day and expecting the new members to collect treasure.