Shredder, Shadow Master

The token copies will have Shredder's abilities.

In the unusual case where Shredder becomes a copy of something else while his last ability is on the stack but before it resolves, the tokens will enter as a copy of whatever Shredder is copying.

Although the token copies created by Shredder's first ability enter attacking, they were never declared as attacking creatures. Abilities that trigger whenever a creature attacks won't trigger when those tokens enter attacking.