DC 15: Penguins dwell near snow dragon lairs, maintaining a safe distance but bringing sacrifices to their god. Most snow dragons ignore penguins but those that take an interest in its penguin cult can become more dangerous.
DC 20: Penguins are skilled at trap making, which they use to capture fish and sacrifices for their god.
A standard long range penguin patrol is comprised of
2 Penguin Dragonshields (level 2 soldiers)
2 Penguin Slingers (level 1 artillery)
4 Penguin Minions (level 1 minions)
Penguins are on pages 167-169 of the Monster Manual
Mourningstar Campaign