Moonshadow said:
Just to add on, a heavy weight is a wolf 130 pounds or more (goes up to 150lbs)
They get a damage increase, but their agility is a little lower. I am unsure of the exact numbers at the moment. I think theres a guide somewhere about it
The weight guide on how damage and agility get effected
75-89 pounds +5 Agility -5 Damage
90-109 pounds +2 Agility -2 Damage
110-129 pounds -2 Agility +2 Damage
130-150 pounds -5 Agility +5 Damage
There are however wolves whose full grown weight are under 75 pounds that have been turning up as of late.
I'm unsure if wolves weighing less than 75 pounds is a bug/glitch or if it's something that is supposed to be able to happen; especially since when weight was added to the game the lowest possible weight your wolf could be was 75 pounds.
Because of this, it's not known if wolves who are under 75 pounds upon reaching their full weight have better agility but hit less damage than 75-89 pound wolves do, or if they have the same gained agility and decrease damage as them
Winter Month: 3 
Day 
Sleet
