The Cup of tea is an unobtainable item encountered during Zogre Flesh Eaters. It is found in the room of Sithik Ints in Yanille, but cannot be picked up.
During the quest, the strange potion should be used on the cup of tea to turn Sithik into an ogre, whereupon he reveals the secret to making Relicym's balm and brutal arrows.
When the "take" option is selected, Sithik Ints yells at the player, Hey! What do you think you're doing? Leave my tea alone!. When a telegrab is attempted, he will say Hey! What do you think you're doing? Don't go casting that kind of spell anywhere near my tea! Leave my tea alone you telegrabbing fiend!