The Hippocampus is a Divine pet added during Part 3 of the High Tide Harvest Event in Grow a Garden. It exists only within that event, and it sits at the top of the reward rarity chart, so most players will donate pets many times before one appears.
Quick answer: Donate any pet to Shelldon on the High Tide Harvest sub-island, wait one hour for the conversion, then open the Pearls you receive. Each opened reward has a 0.2% chance of being the Hippocampus.

Where to find Shelldon and start the Hippocampus roll
The Hippocampus comes only from the Shelldon Rewards feature. Shelldon appears on a separate sub-island tied to the High Tide Harvest Event, and he takes pet donations in exchange for random rewards. There is no shop purchase or direct unlock for this pet.
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Every reward you open carries an independent 0.2% chance of being the Hippocampus. Because the roll happens each time you open your Pearls, the practical path is simple. Keep donating pets, keep waiting out the one-hour timer, and keep opening the results until the pet lands.
You will know it worked when the Hippocampus appears in your inventory as a claimed reward after opening a Pearl. If a Pearl opens into any other item, that roll missed and you simply feed Shelldon another pet.
| Detail | Value |
|---|---|
| Rarity | Divine |
| Source | Shelldon Rewards (High Tide Harvest Event) |
| Cost per attempt | One donated pet |
| Conversion time | 1 hour |
| Drop chance | 0.2% per reward opened |
Tidebound Steed passive and what it does
The Hippocampus runs the Tidebound Steed passive, which supports both your other pets and your crops on a timer. Every 31 minutes it channels a current that lasts 10 seconds, and both effects fire during that window.
- Every pet within 30 studs gains an extra 90 XP per second for the 10-second current, which speeds up leveling for nearby companions.
- Every fruit has a 3.5% chance to gain the Sandy Mutation.
- A fruit that already has Sandy is upgraded to Tidal, and a fruit that already has Tidal is upgraded to Gold, raising its sell value.
Note: The mutation upgrade chain only moves in one direction, from Sandy toward Gold. To benefit most, keep the Hippocampus active alongside crops that can pick up or already carry those water-themed mutations, and keep other pets close so they catch the XP burst.
The Hippocampus is one of the strongest support pets from the High Tide Harvest Event because it stacks faster pet leveling with mutation upgrades that raise crop value over time. The 0.2% drop rate means it takes patience and a steady supply of donated pets, but once you own one it keeps paying off across long play sessions.






