Dear Aternos-Team,
can you please add the Inventory Pets Mod to 
Aternos.
Link -> https://minecraft.curseforge.com/projects/inventory-pets
The Inventory Pets mod add some Cute minecraft Vanilla pets as item in your inventory.
When you have the pet in your Hotbar than is the Pet some special effects.
I hope you add the mod . Thanks.
Your, 12er.