Breeding Structure

"Breed new monsters! ' "Select individuals with different elements. Complex combinations are unstable and may turn out like a parent."'

The Breeding Structure is a nearly mandatory structure on every island. It allows you to the combine the elements of two parents (inputs) into one single child (output).

Breeding Chart
A quick reference chart for breeding new monsters can be found here.

General Breeding Rules
Monsters of the same species cannot breed. If a monster is placed on one side of the Breeding Structure, all other monsters of the same type will be greyed out, and unable to be selected on the other side.

When breeding two eligible parents, their elements are combined into a pool. If there are no elements repeated, then the offspring could potentially be a new species, consisting of all of the elements combined. If a conflict occurs, the resulting offspring will be one of the parents. Even with a correct combination, it is still possible to have an offspring that matches one of the parents.

Example 1: Breeding a Maw (Water, Cold) with a Clamble (Plant, Earth, Cold) contributes 4 different elements to the pool (Plant, Earth, Cold, Water).

Although the Entbrat consists of Plant, Earth, Cold, and Water elements, it cannot be bred with this combination because the Cold element was repeated.

Since there were repeated elements, the resulting offspring will be one of the parents: Maw (2 elements) or Clamble (3 elements).

Example 2: Breeding a Pummel (Plant, Earth, Water) with an Entbrat (Plant, Earth, Cold, Water) will only result in the Pummel parent.

This is because elements are repeated, and the 4-element monsters cannot be the result of "incorrect" breeding combinations. The 4-element monsters can only be the result of valid breeding combinations.

Double Element Monsters
Generally the easiest to breed and hatch, two-element monsters simply require two single-element monsters. For example, a Tweedle and a Potbelly should breed to create a Dandidoo. These breeding combinations appear to have 100% success rate.

Triple Element Monsters
These are slightly harder to breed and hatch, as a two-element monster and a single-element monster are required, and sometimes the baby will take the parents species instead. For example, if the breeding is successful, a Quibble and Mammott would create a Congle.

Quad Element Monsters
The hardest of all to breed and hatch, most of the time you will breed a parent by accident.

The player can breed these by pairing 2 two-element monsters or breeding a three-element and a single-element monster together. Here are two examples of trying to make a Deedge:

Maw + Dandidoo

Bowgart + Tweedle

The combinations of three-element and one-element monsters have higher success rates for breeding a Quad Element Monster than using a pair of two-element monsters. Otherwise, there currently is no evidence that any specific combination for any monster is more successful than another.

However when breeding for Quad Element monsters, many will choose which combination based on the breeding times of the parents, so that "failures" can be moved from the Breeding Structure to the Nursery at predictable or regular intervals without using diamonds to speed the process.

For example:


 * Using a pair of two-element monsters to breed a Deedge: Pango and Oaktopus

With each failed attempt, regardless of which parent is returned, the result is a monster that breeds in 8 hrs, so every 8 hrs an egg will hatch from the Nursery and one can be moved from the Breeding Structure to the Nursery.


 * Using a 3/1 combo to breed a Deedge: Spunge and Mammott

With each failed attempt, the result will be an egg that takes 12 hrs or one that takes 2 minutes. This can result in a Mammott egg sitting complete in the Breeding Structure waiting nearly 12 hrs for a Spunge egg to finish its time in the Nursery. Since the result of a failed attempt is random, it can be hard to predict how often eggs will be ready to be moved - if several Mammott eggs are returned in a row, then several breeding attempts can happen in a matter of minutes. However if a Spunge egg is returned, then no more attempts can be made for 12 hrs (unless diamonds are used).

As such, the method used depends on the player's goal. If the goal is to breed a Quad Element monster, 3/1 combinations are recommended due to a higher success rate. If the goal is to sell unwanted monsters for money, then breeding a pair of two-element monsters can result in more regular intervals while still providing the chance of breeding a Quad Element Monster.

If a Quad Element Monster is put in the Breeding Structure with another monster, the result of the breeding attempt will ALWAYS be that other monster (the only exception has been when certain Limited Time Monsters are available). Thus if breeding to sell unwanted monsters, you can breed a target monster with the Quad Element Monster and know exactly what the results will be. This can be used to sell monster eggs at regular intervals if the same combination (or one with equivalent breeding times) are used repeatedly.

Limited Time Monsters
​Some monsters do not follow regular breeding requirements, instead requiring specific monsters as parents and a combination that is usually considered "unstable". Examples include the Punkleton, a limited Halloween monster that was bred using a Bowgart and a T-Rox, and the Yool, which is bred during the Christmas season with a Thumpies and a Deedge.

Limited Time Monsters are harder to breed than non-limited monsters, leading some to presume that the combinations are not correct.

Wubbox and the Ethereals
With the addition of the Wubbox and then the Ethereals monsters, it appears there may be fundamental, and permanent, changes to the breeding rules. The Wubbox added another element, but as of yet cannot be placed in the breeding structure. The Ethereal monsters appear to be the result of breeding an island's 4-element monster with ANY of the 3-element monsters available (although given the rarity of the monsters, not every combination has been confirmed). This obviously results not only in duplicated elements (like the Limited Time monsters do), but also up to four different end combinations (unlike the Limited Time monsters which only have one combination).

The Ethereals appear to be even rarer than even Limited Time monsters, with suggestions that the chance of success is around 1%.