Can I use Dunsparce's "Return" attack with 6 or more cards in my hand?
Yes, it will do 10 base damage and you will not draw any cards.
Source: Unleashed FAQ (2010-05-13), PUI Rules Team (2010-05-13)

Relevant cards

Note: All applicable cards may not be listed below.
SWSH3_5
SWSH3_5
SM12_89
SM12_89
HGSS4_28
HGSS2_29