The Collaborative International Dictionary of English v.0.48:

Mugger \Mug"ger\, n. Also Muggar \Mug"gar\, Muggur \Mug"gur\
   [Hind. magar, fr. Skr. makara sea monster.]
   The common crocodile (Crocodilus palustris) of India, the
   East Indies, etc. It becomes twelve feet or more long.
   [Webster 1913 Suppl.]