A mixture of pug- and tenacious, however, unbeknownst to me at the time, Pugnacious is an actual word.

Tenacious:
1. Holding or tending to hold persistently to something, such as a point of view.
2. Holding together firmly; cohesive: a tenacious material.
3. Clinging to another object or surface; adhesive: tenacious lint.
4. Tending to retain; retentive: a tenacious memory.