'-od's 'n' '-en's: 3/13ths of an ABC (11)

Arthropod as word ends ‘-od’; 

as bug, it's flaw'd 'cuz shodd'ly shod. 

Bogeymen as word ends ‘-en’; 

as trolls, they're less-than-pleasant men.

Cattle prod as word ends ‘-od’; 

as used, 'twill bruise a bovine's bod. 

Denizen as word ends '-en’; 

as citizen, was alien.

Emerod as word ends '-od';

as sore, it's more an act of God.

Foramen as word ends '-en';

as cut, it's...but that, fratr,' were then...