Who is the bulldog?

[persephonegladrags]

Been lurking on the HPFGU lists for some time, but have never posted 
before.  Now find that two of my favorite things--Harry Potter and 
bulldogs!--have come together, and I can't find the information I'm 
looking for ANYWHERE.  Does anyone here know who the bulldog in the 
PofA movie is?  Where does he come from, whom does he belong to, who 
is his trainer?
Thanks!
PG