Birth (Creature) ability? Where is it from? (3.X)

[flappeercraft]

So on the absolute monster that is the 71 templated tarrasque made by Milov3 (props to him, also will put link below) there is an ability called Birth Tarrasque which comes from a template, I don't even have half the books where the templates are from and haven't heard of about half of those templates either so I need help locating where it comes from. Anyone know?

http://www.giantitp.com/forums/showthread.php?304556-Apocalypse-The-Tarrasque-Templates-WIP

[Necroticplague]

So on the absolute monster that is the 71 templated tarrasque made by Milov3 (props to him, also will put link below) there is an ability called Birth Tarrasque which comes from a template, I don't even have half the books where the templates are from and haven't heard of about half of those templates either so I need help locating where it comes from. Anyone know?

http://www.giantitp.com/forums/showthread.php?304556-Apocalypse-The-Tarrasque-Templates-WIP

The actual ability is called Generate Spawn (SU). It's from the Legion template. You can actually tell because of typo in the writeup.

Birth Tarrasque (Su): As a standard action, an Apocalypse can generate a number of spawn statistically equivalent to a Tarrasque. Apocalypse may create [#] spawn a number of times per day equal to [one-quarter of their Hit Dice (round up)]. [The die type used to generate this random number is the closest die type equal to one third of the legion’s Hit Dice (round up).]

[flappeercraft]

Thank you necroticplague. Your help has been really useful.

Also, do you know if Book of templates is 1st or 3rd party?

[Necroticplague]

Thank you necroticplague. Your help has been really useful.

Also, do you know if Book of templates is 1st or 3rd party?

Yes, I do. It's completely third party, by Silverthorne Games, lacking any "dnd product" language or the DnD logo.