When you add Hit Dice to a druid’s (or ranger’s) animal
companion as the master’s level goes up, does the animal
get any bigger? For instance, when a druid has a wolf
companion, the wolf starts out with the standard 2 Hit Dice
and is size Medium. By the time the druid is 3rd level, the
wolf has 2 bonus Hit Dice. According to the wolf entry in
the Monster Manual, an “advanced” wolf with 4 Hit Dice
would be Large. Is the example companion wolf also
Large?
An animal companion doesn’t get bigger when it adds extra
Hit Dice for the master’s levels. The advancement entries for
creatures, and the rules for advancing monsters, refer to
unusually powerful specimens that are simply tougher (and
perhaps bigger) than normal for their kinds.
