Toughie friends are either the smarty friend's "henchfluffies" or "enforcers".
A toughie's role in the herd Edit
Most feral herds of fluffy ponies are led by a dominant alpha fluffy, commonly called the smarty friend, or "smawtie fwend" by the fluffies themselves. More often than not, the leadership of the smarty friend is authoritarian and cruel, as the smarty friend decides which member of the herd gets how much to eat, where the resting place is, which fluffy is allowed in the fluffpile, and if a fluffy pony gets to live or not. To enforce its will, as well as protect itself from retribution, the smarty friends needs a posse of enforcers selected from its most loyal, and the toughest and strongest followers/friends, the so-called toughie friends (almost all of them male fluffies). The toughies are the eyes and ears of the smarty friend, as well as its muscles.
Most toughies are earth fluffy ponies, as they are the strongest, hardiest, and largest fluffies of the three common types of fluffy ponies, followed by unicorn fluffies. Pegasus fluffies are unlikely to be toughies, as most of them are too flimsy and weak, but if a fluffy is well fed and healthy growing up it still has a chance to become a toughie if needed by the smarty.
Depending whether the herd has a good smarty friend or not, toughies can be seen as the herd protectors or cruel enforcers of the smarty's law. Toughies perform many duties. They are tasked with killing and captured fluffy ponies from a rival herd, making sure that no food gatherer fluffy is hoarding food for itself, forcing worker fluffies to continue digging and building the nest, punishing stallions and mares that have mated together without the smarty friend's consent, protecting pregnant mares from danger and possibly protect the herd from danger from other raiding fluffies. A toughie friend is given many responsibilities, and is adequately rewarded for its loyalty by the smarty friend. Toughies get the second-largest share of the food, a good sleeping place, and the most desirable mates for sexual recreation. The position of toughie friend is highly sought out for this reason. Ironically, because they're strong and well-fed and many have an ego almost as big as that of the smarty friend as a result of their privileged position and duties, the most likely usurper trying to dethrone the smarty friend and take its place come from the ranks of the toughie friends.
Toughie behavior Edit
Just like smarties, toughies puff up their cheeks in an attempt to make themselves look bigger and more intimidating. This works well against fluffy ponies, but not very well against anything else that the fluffies call monster (or 'munsta'). Because they bully weaker fluffies into submission, toughies erroneously believe that they can also do the same with much larger and far more dangerous opponents, like dogs, cats, and most dangerous of them all, humans. They will join the smarty friend in humiliating and (futilely) intimidating their targets by defecating on them with 'sorry poopies' and insulting them, or cheer the smarty on for doing such a brave and audacious deed. This causes the highest numbers of attrition among toughies, as they are closest to the dangerous being they sought to scare off. Toughies will try to rescue their smarty friend leader at first, but if the opponent gruesomely finishes the smarty off, the toughies will quickly falter and panic, either fleeing, or attempting to "hide" by closing their eyes with their hooves and babbling fearfully to themselves that they are hidden and cannot be found by the 'munstah'. If the smarty was atypically smart enough (or just lucky) to not stand the closest to the 'munstah', it might order the toughies to continue attacking the enemy, using them as meat shields to buy itself time for it, and possibly the herd. to flee. Their numbers then need to be replaced by other surviving fluffies, which only rarely works, as those fluffies tend to be weak from maltreatment, malnourishment, and constant hard work.
If one or more toughie survived, and the smarty died, one of the toughies will become the next smarty. As most unicorn fluffies believe themselves to the be smartest and act the most confident in their abilities, it is they that generally become the smarty's successor. Toughies that survive such a failed attempt at attacking a 'munstah' will blame the original smarty for their fate, if it is still alive. It is such disastrous events that usually lead to toughies thinking about replacing the current smarty, and punishing it for leading such an ill-fated attempt at conquering land, shelter, and food. When a smarty fluffy is dethroned, most of the herd's other survivors will also join in the lynching of their former smarty friend.
In general, toughies are not born, they're chosen by the smarty. Most toughies were the 'bestest babbeh' of a litter, and as such are well-fed, healthy, and strong by fluffy pony standards. Most toughies become toughies because the smarty ordered them to do things that only a toughie can do, such as spying on the rest of the herd, accompanying the smarty on a raid against a rival herd, punishing a fellow herd member, or raping a new mare into submission as a sign of the smarty friend's authority. Membership in the circle of toughie friends surrounding the smarty friend is generally for life. If a toughie is injured too much to do most of the work of a toughie, it might be assigned to stay behind and protect the pregnant dams and still be given favorable treatment, unless the smarty friend is really ungrateful and now forces the ex-toughie to work itself to the bone just as the rest of the herd.