Timmy the Cruel

Crusaders' Square
Clear the Crimson defenders outside the Scarlet Bastion before entering the building. Watch the cleared courtyard behind the group for Timmy the Cruel as the defenders fall. Fight Timmy there if the encounter appears, rather than carrying its extra melee attacks into the next Crimson pull.

Timmy the Cruel
Elite UndeadTimmy's extra attacks and health-stealing claw turn the courtyard pull into a tank-survival fight that becomes more dangerous during Enrage.
Abilities

Thrash
Adds a chance to do two additional attacks.
Thrash creates extra-attack bursts; keep enough tank health and mitigation to survive several hits together.

Ravenous Claw
Ravenous Claw both hurts its victim and restores Timmy's health; keep damage focused on Timmy rather than letting the courtyard pull spread.

Enrage
Use a tank defensive during Enrage while the group finishes Timmy.
Tank- Keep Timmy in the cleared courtyard instead of entering the Bastion with the ghoul attached. Hold a defensive for Enrage and the extra attacks from Thrash.
Healer- Begin with the tank healthy enough for a Thrash burst, then restore the health Ravenous Claw removes. Do not start recovering mana just because Timmy is nearly defeated; Enrage makes the finish more dangerous.
Damage- Finish Timmy before taking another Crimson pull. Spend damage cooldowns on the Enrage finish so the tank spends less time taking enraged Thrash bursts.