If, during your declare attackers step, Ursine Monstrosity is tapped, is affected by a spell or ability that says it can't attack, or hasn't been under your control continuously since your turn began (and doesn't have haste), then it doesn't attack
Simulacrum Synthesiser allows you to spit them out onto the battlefield like clockwork, whenever an Artifact of mana value 3 or higher enters the field under your control
The History of Fear First things first
It is described on eBay as being in near mint condition (we should hope so for a price tag like that)
He can then nip in in the skies for damage, helping you to make the most of Tymna's ability as well
For the low cost of two mana, this 1/1 Orc Pirate provides an anthem effect whenever it attacks, buffing each Pirate you control by +1/+1 for each time you've cast Vargus from the Command Zone in the game