Here's why it's unclear:
* "Mohd" doesn't have a clear meaning in this context. It might be a misspelling of "Mohammed," a common name in some cultures.
* "Dog with big mouth" is a common metaphor used to describe someone who talks too much or gossips. However, it's typically used without any specific name attached.
If you encountered this phrase in a specific context, it would be helpful to understand the situation and the speaker's intention to decipher its meaning.
Without more information, it's impossible to give a definitive answer.