This tip is for those who like / want to use interdimensional potion in their house decorations.
It is possible to obtain an infinite amount (however time-limited) of these potions in the npc called Zizzle:
The npc is located on the bottom floor of the Emperor's castle, in the quest Wrath of Emperor Quest, to obtain the potions you must speak to the npc:
Player: Hi
Player: Potion
Player: YesThis Potion can be obtained once every hour.