Like all other sanctuary animals, players can only have two of them.
Hippopotamus calves have two different appearances: brown and grey.
If players tap on the brown hippo calf, butterflies appear. The calf watches them and then stomps its feet.
If players tap on the grey hippo calf, it crosses its eyes and then farts.
Unlocking and placing
Unlike other animals, hippo calves cannot be bought. Players must unlock them by finding puzzle pieces (which are collected in a log book). 36 pieces are required for each animal.
Once the puzzle for the hippo calf has been completed, players are asked to upgrade the hippo house, which does not cost anything. The hippo calf is then "airlifted" into the sanctuary by balloons.
When given a wheat bundle hippo calves eat then roam the sanctuary for ten hours and finally fall asleep. Players can immediately wake them up to receive 25 xp per animal. Hippos stay asleep otherwise.
Hippos which have been woken up but are not fed for a long while cannot fall asleep and wander around looking sleepy and tired.
Each hippo unlocks specific decorations as listed below:
- The brown hippo calf unlocks Barrel Cacti and Small Acacia Trees.
- The grey hippo calf unlocks White Ice Plants and Dragon Blood Trees.