Can you kill Ancient Spawn of Morgathla without killing bosses for WZ 4-5-6?

Question

I was invited to kill that boss but I don't have Bosses for WZ 4-5-6, can I join the team?

Answer 1

No, simple as that, killing all three bosses at least once is a requirement to enter the final boss

"After defeating all 3 Warzones bosses, you'll have the chance to battle the Ancient Spawn of Morgathla."

Source: https://tibia.fandom.com/wiki/Dangerous_Depths_Quest 
Also, I have done this boss before 

Answer 2

No, you can't. you need defeat all 3 warzones bosses first to have the chance to fight against Ancient Spawn of Morgathla. also you need 3 items to fight him.

Mallet Head, dropped by The Baron from Below from Warzone 4;

Mallet Handle, dropped by The Count of the Core during Warzone 5;

Mallet Pommel, dropped by The Duke of the Depths during Warzone 6.