Found 4 phrases starting with MR:

mr. all business	Someone who acts very business-like and serious and focused on the job at hand, either at the moment or all the time	Rate it:
mr. charlie	Your boss man.	Rate it:
mr. potato head	A popular, commercially available, children's game featuring a plastic potato onto which a variety of features can be added for amusing results.	Rate it:
MRW	Initialism of maximum ramp weight.	Rate it:

We need you!

A Otts and

B Moxy

C Mocks and

D Oxen