Learn German: Der Champion soll das allerschönste Fell haben. - The champion is said to have the very most beautiful fur.

Adding aller- to a superlative adjective intensifies it to the absolute maximum. While das schönste Fell means "the most beautiful fur", adding the prefix creates das allerschönste Fell, meaning "the very most beautiful fur" or "the most beautiful fur of all".

Why is soll translated as "is said to" here instead of "should"?

In German, the modal verb sollen is frequently used to express hearsay, rumors, or claims made by other people. When used this way, it translates to "is said to" or "is supposed to" rather than expressing an obligation or advice like "should".

Why does allerschönste end in an -e?

It follows the standard rules for weak adjective declension. Because it comes after the definite article das and modifies the neuter, accusative noun Fell (fur), the superlative adjective takes the ending -e. The prefix aller- doesn't change how the adjective declines.

Where does the prefix aller- actually come from?

It is historically the genitive plural form of the word all. So, when you use aller- with a superlative, you are literally saying "the most ... of all". It can be attached to almost any superlative adjective to give it this extra boost.