Jared Grace is nine.  Jared is rowdy, short-tempered, and brave.  Jared is the exact opposite of his twin, Simon.  Jared is the one who discovers the Field Guide and insists on keeping it.  Jared is one of the main protagonists and is often in trouble mainly because of the Field Guide.  Teaming up with a wide variety of creatures, he must defeat Mulgarath and destroy the guide.

Mallory Grace is thirteen.  Mallory is very athletic and tough.  She is very good at fencing and the trio uses her swords for defense.  Mallory sides with Simon on destroying the Guide and the target of Thimbutack (a boggart) in the first book.  Mallory is a main protagonist and is vital in the story ending.

Mallory Grace is thirteen.  Mallory is very athletic and tough.  She is very good at fencing and the trio uses her swords for defense.  Mallory sides with Simon on destroying the Guide and the target of Thimbutack (a boggart) in the first book.  Mallory is a main protagonist and is vital in the story ending.

Arthur Spiderwick is over 100 years old.  He is the creator of the Field Guide and the Grace children’s great-great uncle.  He was held captive by a bunch of elves for attempting to trick them about the Guide.  Arthur is a kind man, highly inquisitive, and a loving father to Lucinda Spiderwick, Jared’s, Simon’s, and Mallory’s great-aunt.  IN the last book, he gives Jared advice on how to take down Mulgarath.

Thimbletack is a brownie and a boggart in the first book.  Like all brownies, Thimbletack is bound to a household, in this case the Spiderwick estate.  Thimbletack is first discovered by Jared who guesses his presence with the help of the Field Guide by appeasing Thimbletack by making him a house; he turns back into a brownie.  Thimbletack as a brownie is helpful and kind and loves to speak in rhyme.  He often warns Jared, Simon, and Mallory of danger and provides a seeing stone (see the plot).

Mulgarath is an ogre.  Like most of his species, Mulgarath is clever and strong, but selfish and vain.  An expert shape shifter, Mulgarath tricks the Graces and imprisons Helen Grace, their mother. However he is defeated by Jared and Hogsqueal (a hobgoblin) because of his vanity.

Elves play a rather large role in the Spiderwick Chronicles mainly because Arthur is their prisoner. Jared, Simon, and Mallory have three main encounters with the elves. The first encounter is in Lucinda’s Secret when they are looking for the field guide. The second encounter is in The Wrath of Mulgarath when Jared goes to the elves to request a meeting with Arthur. The last encounter is also in The Wrath of Mulgarath when the Graces, Lucinda, Thimbletack, and Hogsqueal come to return the guide.

Griffins have a very large role because of Bryon, the griffin that Simon rescues from a goblin mob. After healing, Bryon continues to stay on the Spiderwick Estate. He helps get to Mulgarath in the last book by killing several dragons and eating the babies. Bryon also delivers others to the bases for their final goodbye.

Ogres are represented by Mulgarath. They are the villains in the story, like Puss in Boots. They are mainly are described as big, mean, clever, and strong. Despite this they are defeated because of their vanity and laziness. In both stories, both ogres are killed the same way, by being eaten.