Golem

 and the Golem Sisters are bosses from that appear in Zeal Palace and Ocean Palace in the Antiquity era.

First Encounter
During the party's first attempt to get into the Ocean Palace, they encounter Dalton for a brief moment. Dalton then summons one Golem to attack the party. This battle will likely end in the Golem's favor, but that doesn't mean the game is over. The players are subsequently teleported to Ocean Palace.

Strategy
Having finally arrived at the Ocean Palace, the party eventually runs into Dalton again, who summons two Golems to fight the party. They can be extremely difficult to beat, because there are two of them, and they are also extremely fast(Speed is probably at 16, so unless you've been really saving up on Speed Capsules, it'll be difficult, even with Crono's Swallow sword equipped. Setting the ATB mode to "Wait" might also help.) They also copy your elemental attribute of the attack you use (this applies to physical attacks as well). Also, if you went around and opened the sealed boxes in all times, and kept all the colored vests, though this yields only two of each color. Stocking up on Ruby Vests in Prehistory will suffice, as they deflect 50% of fire attacks. If Lucca is in group, outfit her with Taban's Helm and Taban's Vest. Equip vests, and any MP reduction accessory. Start the fight with applicable spells, i.e. Ruby Vest absorbs Fire, casting Fire on the Golems or any dual techs causing fire damage causes them to retaliate with moves of the same color, thus all Golem spells heal the party.

Trivia

 * It is possible to kill Golem in the Zeal Palace. If successful, Dalton gets angry and shoots lightning at Crono and the other two teammates. If the battle is lost, the three heroes are captured. (This does not end the game).