Astrid, Undaunted General

If a spell or ability would cause you to sacrifice a permanent, you may put it on top of your library
instead of putting it anywhere else.
{r}: Target attacking creature you control gets
+1/+0 and gains trample until end of turn.
Sacrifice it at the beginning of the next end step.
"We raid, we kill, we conquer. To our death- and
beyond."