Mutate is a new mechanic in Ikoria. A lot has been said about how it works, but cloning is something I can't find mentioned on the net. Not sure if the comp rules have been updated yet, but my impression is that as it is one creature, a clone would get all of the mutated abilities. Is this correct?
Cloning a mutated creature copies all the existing mutations
This interaction has been put together by a modification of the first layer of continuous effect interactions and two new rules.
613.1a Layer 1: Rules and effects that modify copiable values are applied.
Previously, this layer applied 'copy effects'. Now it's been generalized to apply 'copiable values', of which includes the newly created category of "merged permanents"
721.2a A merged permanent has only the characteristics of its topmost component, unless otherwise specified by the effect that caused them to merge. This is a copiable effect whose timestamp is the time the objects merged. (See rule 613.2.)
And mutate, the effect causing the permanents to merge, modifies the characteristics to include the rules text of the other objects.
702.139e A mutated permanent has all abilities of each card and token that represents it. Its other characteristics are derived from the topmost card or token.
It really depends on how mutate is handled by the new rules.
However, the easiest way to handle it, from a rules standpoint, would be to generate a text changing (or ability granting) continuous effect. In this case, only the top creature would be copied.
I cannot think of a way to make the mutated abilities copiables safe from defining the mutated creature as a new card. It is possible they might go this way instead (similar to meld cards).