The Hall of Presidents?

Automaton (from The Adventure Zone)
Medium construct, no alignment "Armor Class 15""Hit Points 12 (2d8+3)""Speed 30ft.""STR 12 (+1)""Dex 14 (+2)""Con 12 (+1)""Int 10 (+0)""Wis 10 (+0)" Cha 11 (+0) Senses Passive Perception 10

Languages Common

Challenge 2 (450 XP)

Axiomatic Mind The automaton can't be compelled to act in a manner contrary to its nature or its instructions.

Actions
Fist Melee Weapon Attack +3 to hit, reach 5 ft., one target. Hit 4 (1d6+1) bludgeoning damage.

Shortbox Ranged Weapon Attack +4 to hit, range 50/320 ft., one target. Hit 9 (2d6+2) damage.

Story
Automatons will rise and begin to slowly surround the players. They need to finish the puzzle "on the floor" before the automatons reach them, or they will begin to attack.

Presidents

 * Bill Clinton
 * James Madison
 * Jimmy Carter
 * John Quincy Adams
 * Thomas Jefferson
 * Gerald Ford
 * FDR in a box