Which bosses drop the Iluminator outfit addons?

Question

After completing the Between the Lines quest you receive the outfit Iluminator but to get addon 1 and addon 2 you need to kill 3 bosses so all of them has a chance to drop these items?

Answer 1

According to VDA Pedro (as you can see here in this link) you can drop:

Scallop shell (Addon 1): Tropical desolator (the mini boss located on Liberty Bay)

Sand-filled horn (Addon 2)  : Wrathful Archivist (the mini boss located on Yalahar)

Answer 2

After completing the Between the Lines quest, you get access to 3 new Archfoe bosses. However, only 2 of them drops the addons.
Tropical Desolator - Liberty Bay - Drops Scallop Shell (Addon 1) 

Wrathful Archivist - Yalahar - Drops Sand-Filled Horn (Addon 2) 

Images Source: https://www.tibiawiki.com.br/wiki/Between_the_Lines_Quest