Howltusk is a unique Great Helm.
Due to its knockback and its ability to make enemies flee, it is a good helm for keeping enemies away from the user. Howltusk provides a good amount of mana to use skills, as well as absorbing damage.
Stats

Howltusk
Great Helm
Defense: 64
Required Level: 25
Required Strength: 63
Durability: 40
35% Damage Taken Goes to Mana
+80% Enhanced Defense
Magic Damage Reduced By 2
Attacker Takes Damage of 3
Knockback
Hit Causes Monster To Flee +25%
Normal Helms — Biggin's Bonnet (Cap) • Tarnhelm (Skull Cap) • Coif of Glory (Helm) • Duskdeep (Full Helm) • Howltusk (Great Helm) • The Face of Horror (Mask) • Undead Crown (Crown) • Wormskull (Bone Helm)
Exceptional Helms — Peasant Crown (War Hat) • Rockstopper (Sallet) • Stealskull (Casque) • Darksight Helm (Basinet) • Valkyrie Wing (Winged Helm) • Blackhorn's Face (Death Mask) • Crown of Thieves (Grand Crown) • Vampire Gaze (Grim Helm)
Elite Helms — Harlequin Crest (Shako) • Steel Shade (Armet) • Veil of Steel (Spired Helm) • Nightwing's Veil (Spired Helm) • Andariel's Visage (Demonhead) • Crown of Ages (Corona) • Giant Skull (Bone Visage)