gistfile1.scala

trait Animal   { def name: String; def word: String; def talk() = println(s"$name says $word") }

trait Flying   { def fly()  = println("flap flap") }
trait Swimming { def swim() = println("splish splash") }
trait Walking  { def walk() = println("stomp stomp") }

def newAlligator =
  new Animal with Walking with Swimming { val name = "alligator"; val word = "grrr" }
  
def newDuck =
  new Animal with Walking with Flying with Swimming { val name = "duck"; val word = "quack" }
  
def newGoat =
  new Animal with Walking { val name = "goat"; val word = "baa" }
  
val alligator = newAlligator
val duck      = newDuck
val goat      = newGoat

gistfile2.txt

scala> alligator.talk()
alligator says grrr

scala> alligator.walk()
stomp stomp

scala> alligator.swim()
splish splash

scala> duck.talk()
duck says quack

scala> duck.walk()
stomp stomp

scala> duck.fly()
flap flap

scala> duck.swim()
splish splash

scala> goat.walk()
stomp stomp

scala> goat.talk()
goat says baa