Ancient Pandaren Fishing Charm
This item is needed for The Relic Hunter (Title) and Is Another Man’s Treasure (Achieve)
Since becoming a ‘hidden’ toy it will not show in your collection until you have obtained it
Obtained by speaking to the rarespawn NPC Ghostly Pandaren Fisherman in the Valley of the Four Winds.
You cannot get this toy on a character that you’ve already gotten it on. Meaning that if you played in MoP, got this charm then and later pitched it, you won’t be able to see the Ghostly Pandaren Fisherman again on the same character
To check whether you have found it on a character
/run print(IsQuestFlaggedCompleted(31284))
Map ‘borrowed’ off internet
Gem of Acquiescence
The Gem of Acquiescence is a Hidden Toy added in Battle for Azeroth and is found in a hidden cave beneath the Stormsong Monastery in Boralus.
This toy does not appear in the Toy Box until learned and is also a part of the Treasures of Tiragarde Sound achievement, listed as “Secret of the Depths”.
Guide here – Warcraft Secrets 
Blingtron’s Circuit Design Tutorial
Zandalari Effigy Amulet toy and Haw’li’s Hot Chili toy
Video- Top 10 Rarest Obtainable Toys in WoW
10.) All-Seer’s Eye: (0:31)
9.) Barrel of Eyepatches/Bandanas : (2:09)
8.) Hell-Bent Bracers: (3:33)
7.) Smolderheart: (5:06)
6.) Mayhem Mind Melder: (6:18) See through the eyes of the battle pet you currently have out, and can control your pet’s movement.
5.) Stormforged Vrykul Horn: (8:24)
4.) All-Seeing Eyes: (9:43)
3.) Horde/Alliance Flags of Victory: (11:18)
2.) Super Simian Sphere: (13:20)
1.) Unstable Portal Emitter/Vixx’s Chest of Tricks: (14:18)
The Schools of Arcane Magic-Mastery toy
None the Wiser Guild 