The festive season has officially arrived in Build a Zoo, and with it comes one of the biggest updates of the year. Build a Zoo Update 45 launches the much-anticipated Christmas 2025 Event, delivering a wide range of limited-time content, brand-new pets, exclusive rewards, gameplay improvements, and a fresh redeem code for players to enjoy.
Whether you’re a long-time zoo manager or a returning player looking to explore seasonal content, this update adds plenty of reasons to jump back into the game. From snowy weather effects and rare Christmas mutations to Ocean Egg expansions and Big Pet level cap increases, Update 45 significantly expands the overall experience.
Below is a complete breakdown of everything included in Build a Zoo Update 45, including the Christmas event features, store updates, hidden pets, new codes, and quality-of-life improvements.
Build a Zoo Christmas 2025 Event – Overview
At the heart of Update 45 is the limited-time Christmas Event, designed to transform the game world into a festive winter wonderland. During this event, players can experience unique weather conditions, unlock seasonal pets, collect themed items, and earn exclusive rewards that won’t be available once the event ends.
This seasonal update focuses heavily on exploration, hatching, and progression, making it an ideal time to expand your zoo and unlock rare content.
Christmas Limited-Time Event Features
Christmas Weather and Seasonal Mutations
One of the standout features of Update 45 is the introduction of Christmas weather. During the event period, special snowy conditions will appear in the game, changing both the visual atmosphere and gameplay mechanics.
While Christmas weather is active, players have a chance to trigger Christmas mutations, which are exclusive variations of pets that can only be obtained during this event. These mutations add extra value to your collection and offer unique appearances that set your zoo apart.
Additionally, the festive weather creates opportunities to obtain the rare Christmas Mutant Egg, making exploration and timing more important than ever.
Christmas Mutant Egg
The Christmas Mutant Egg is one of the most sought-after items in Build a Zoo Update 45. This special egg can only be obtained during Christmas weather and hatching it may result in a powerful or visually unique Christmas pet.
Because of its limited availability, the Christmas Mutant Egg has quickly become a top priority for collectors and competitive players alike.
New Christmas Pets and Eggs
Update 45 introduces brand-new Christmas pets that are exclusive to the event. These pets are designed with festive themes and special traits, making them a must-have for seasonal collectors.
Players can earn Christmas eggs by actively participating in the event, completing tasks, and engaging with holiday-themed mechanics. Once the event ends, these eggs and pets may no longer be obtainable, adding a sense of urgency to collect them while you can.
Exclusive Christmas Rewards
Beyond pets and eggs, the Christmas Event offers several cosmetic and customization rewards, including:
- A limited-edition Christmas Title
- A festive Home Board
- The unique Christmas Carol Field
- Special Christmas-themed foods
These rewards allow players to decorate and personalize their zoo with holiday flair, making the event both functional and visually rewarding.
Store Updates in Build a Zoo Update 45
New Elite Pet Passes
The in-game store has received major additions with the introduction of two new Elite Pet Passes, designed to speed up progression and improve zoo management efficiency.
The new Elite Passes include:
- Evolution Speed Boost Pass – Reduces the time required to evolve pets
- Pet Placement Expansion Pass – Increases the maximum number of pets you can place in your zoo
These passes are especially useful during the Christmas event when players are hatching, evolving, and managing a larger number of pets than usual.
Limited-Time Christmas Bundle
A Christmas Bundle has also been added to the store for a limited time. This seasonal pack includes:
- Christmas Event Eggs
- Christmas Fruits
- Bonus resources to help speed up progression
The bundle is ideal for players who want to maximize their event rewards without excessive grinding.
Improved Store Navigation
To enhance usability, the store now includes a jump-to-category navigation feature, making it easier to browse items, bundles, and passes without scrolling endlessly. This quality-of-life improvement is especially helpful as the store continues to expand with new content.
Big Pet Level Cap Increase
Progression gets a major boost in Update 45 with increased level caps for large creatures.
- Big Pet maximum level increased to 380
- Big Fish maximum level increased to 110
These changes allow veteran players to further strengthen their rare and high-tier pets, making long-term progression more rewarding. The higher caps also encourage deeper investment into evolved pets rather than constantly replacing them.
New Hidden Pet Added
Update 45 introduces a brand-new hidden pet that has been secretly added to the hatch pool. This pet does not appear in standard listings and may show up unexpectedly while hatching eggs.
Hidden pets are designed to reward curiosity and persistence, and discovering one during the Christmas event adds an exciting element of surprise to the update.
Ocean Expansion – New Eggs and Pets
The Ocean biome has received fresh content in Build a Zoo Update 45, expanding aquatic gameplay.
New Ocean Eggs
Players can now obtain new Ocean Eggs, which feature updated loot tables and the chance to hatch newly added aquatic creatures.
New Ocean Pets
Several new Ocean pets have been added to the game, offering more variety for marine-themed zoos. These pets come with unique designs and behaviors, encouraging players to invest more time in ocean exploration and collection.
The Ocean expansion adds depth to the game and balances the heavy focus on land-based pets.
Additional Optimizations and Improvements
Beyond new content, Update 45 includes multiple behind-the-scenes improvements aimed at smoother gameplay.
These optimizations include:
- Refined UI elements for better readability
- Improved system performance and stability
- Enhanced in-game displays for cleaner navigation
While not always immediately noticeable, these improvements contribute to a more polished and enjoyable experience overall.
Build a Zoo Update 45 – New Code
To celebrate the Christmas Event and Update 45 release, a brand-new redeem code has been introduced:
CHRISTMAS12
This code provides free in-game rewards and should be redeemed as soon as possible, as it may expire after the event period. Players can also check the official Build a Zoo codes tracker page for previously released and still-active codes.
Final Thoughts on Build a Zoo Update 45
Build a Zoo Update 45 delivers one of the most content-rich updates in recent months. The Christmas 2025 Event adds festive charm, exclusive rewards, and rare pets, while the store upgrades, level cap increases, Ocean expansion, and hidden pet keep long-term players engaged.
Whether you’re hunting for Christmas mutations, leveling up Big Pets beyond previous limits, or exploring new Ocean eggs, this update offers something for every type of player.
That wraps up everything you need to know about Build a Zoo Update 45: Christmas Event, New Codes, Pets, and More. Be sure to take advantage of the limited-time event before it ends—and happy zoo building! 🎄🐾