猴头 and 蛙蛙鱼 are NOT Cantonese dishes at all

猴头 - as far as I know, belongs to Northern China.

蛙蛙鱼 - belongs to some inland region as this is from river or swamp.

Being at the coastal area, Cantonese fish dishes mainly are seafoods, the fresh water fishes dont include such "strange looking" fish 蛙蛙鱼.

Since I grew up in Hong Kong, I think I am qualified to make comments to the above.