In Harry Potter Wizards Unite you must collect Foundables in order to complete your Registry.
However, some creatures and objects are more difficult to find than others!
In the live Registry, Foundables are categorised into five groups of threat level — Low, Medium, High, Severe and Emergency.
However, according to information found in the game data, Niantic seems to have gone further, grading the rarity level of a Foundable from 1 to 16 (with 1 being the least rare).
- Not rare at all (such as Grim Fawley's Journal and many others found in the Mysteries tab)
- Very ordinary (such as Luna Lovegood or Ginny Weasley)
- Ordinary (such as the Golden Snitch or Peeves)
- Extremely common (such as Swooping Evild)
- Very common (such as Professor McGonagall)
- Common (such as Quidditch Pitch Stands)
- Normal (such as Nose-Biting Teacup)
- Uncommon (such as the Ravenclaw Crest)
- Uncommon (such as the Ministry Time-Turner)
- Very unusual (such as Fred Weasley's Wand)
- Quite rare (such as Quiberon Quafflepunchers)
- Rare (such as Veritaserum)
- Very rare (such as Adult Harry Potter)
- Really very rare (such as Severus Snape's Wand)
- Ultra rare (such as Nagini)
- Extremely rare (such as the Resurrection Stone)
Source
REMEMBER, a beam of light above the Magic Trace means it is much rarer than usual!