Malleability- Malleability is the property of a substance generally metals to be beaten into thin sheets without breaking.
Lanthanides/ Lanthanoids - They are f-block elements of the periodic table.
They are soft and malleable.
For example - Cerium (Ce), Praseodymium (Pm), Holmium (Ho), Thulium (Tm), Erbium (Er) etc. They all are f-block elements (lanthanides) and are malleable.