Take butterfly and name 'Bambi'? (10)
'take' is the definition.
'butterfly and name 'bambi'?' is the wordplay.
'butterfly' becomes 'comma' (comma butterfly is a kind of butterfly).
'and' means one lot of letters go next to another.
'name' becomes 'n' (common abbreviation e.g. on forms).
''bambi'?' becomes 'deer' (the Disney character Bambi is an example).
(Other definitions for commandeer that I've seen before include "requisition", "Take control of for military use", "Appropriate", "Confiscate", "Take control of for military purposes".)