Goblin Barricaders

You and a team of three or more goblins use your proficiency with shields to create a mobile wall of shields which provides full cover for goblins behind the wall

No more than 6 small creatures (including the Goblin Barricaders) may benefit from the cover. Each additional set of three Barricaders allows for 3 other small creatures to benefit from cover.

individually each Barricader has the shield mastery feat

• If you take the Attack action on your turn, you can use a bonus action to try to shove a creature within 5 feet of you with your shield.
• If you aren't incapacitated, you can add your shield's AC bonus to any Dexterity saving throw you make against a spell or other harmful effect that targets only you.
• If you are subjected to an effect that allows you to make a Dexterity saving throw to take only half damage, you can use your reaction to take no damage if you succeed on the saving throw, interposing your shield between yourself and the source of the effect.
• You gain proficiency with shields if not already.