So I was reflecting on how each Dwarf regiment gives me two spare Mastiffs over the weekend (well 3 as IMO the upgrade is 15-20 points too expensive), and threw these together. I have them as infantry based on both the size of the model and the IMO they shouldn't be affected by spears/pikes.
Mastiff Pack - infantry
Troop (5); Sp6; Me4+; Ra-; De3+; At5; Ne8/10; Pts25
Regiment (10); Sp6; Me4+; Ra-; De3+; At10; Ne9/11; Pts45
Special: Headstrong; gain Elite & Vicious vs units with Shambling
Poosycat Pride - infantry
Troop (5); Sp6; Me4+; Ra-; De3+; At5; Ne8/10; Pts30
Regiment (10); Sp6; Me4+; Ra-; De3+; At10; Ne9/11; Pts55
Special: Elite; Crushing Strength (1)
Twisted Mastiff Pack - infantry
Troop (5); Sp6; Me4+; Ra-; De3+; At5; Ne8/10; Pts30
Regiment (10); Sp6; Me4+; Ra-; De3+; At10; Ne9/11; Pts55
Special: Headstrong; Viscious; gain Elite vs units with Shambling
Undead Giant Rats - infantry
Troop (5); Sp6; Me5+; Ra-; De3+; At5; Ne-/10; Pts25
Regiment (10); Sp6; Me5+; Ra-; De3+; At10; Ne-/11; Pts45
Special: Evil Dead; Shambling; Bloodbath
EDIT:
obscenity filter