noun (n)

• someone shirking their duty by feigning illness or incapacity(noun.person)

  Synonym:
  shammer, skulker
  

  source: wordnet30
• In the army, a soldier who feigns himself sick, or who induces or protracts an illness, in order to avoid doing his duty; hence, in general, one who shirks his duty by pretending illness or inability.(noun)

  source: webster1913