This boss is the strongest boss on the island map especially in alpha difficulty, so you are going to have to be equipped very well. You will have to gain a bunch of mutations on your dinosaurs, so they can survive this battle this is coming. This battle is the final battle you will do on the island, before ascending from it. The overseer cave (sometimes referred to as the tek cave) is at the volcano.
Tek Terminal: 428390
It will be very hot in the first part of the cave, but very cold in the actual arena itself, so you are going to bring two types of armoured gear (prefably the ghille armour and the fur armour) and two types of soup (calien soup for hot temperatures and fria curry for cold temperatures) in order to work with the temperature.
To play in beta difficulty, you need to have:
1 Alpha Carno Arm
1 Alpha Raptor claw
1 Alpha Tyrannosaur tooth
1 Beta Broodmother Trophy
1 Beta Dragon Trophy
1 Beta Megapithecus Trophy
In the cave, there are powerful a$$ dinos that are inside the cave. The creatures there have a level of 500 on just difficulty one. But just as if the heat and the high level dinos aren't enough, you also have to be cautious of wild gigas roaming the area too. This is why it is important to bring dinos with good mutation stats to this very dangerous place. Use every gun, weapons and brimstone you and your tames have to fire on those creatures, especially the gigas. Remember to take it SLOW though, no rush.
Once you have teleported to the arena, you start fighting the boss. The boss will spawn plenty of attack drones and defence units. Try focus on killing these first, so that they don't overwhelm you and start killing everything. The overseer starts in its own form which looks like that specimen implant in your arm, and has a shield around it, meaning that it can't be attacked. It is also able to shapeshift into any of the three bosses you have defeated. The megapitchecus, the broodmother and the dragon. When it shapeshifts to the dragon, you will need to use the same method you did when you defeated the dragon. It will then return back to its original form and project a shield around itself. It will then start shooting lasers across the arena. You do not want this laser to hit you. The lasers will dismount you off of your dino if it hits you, and prevent you from moving for a few seconds, so you need to hide behind pillars to avoid this. The boss does this attack, every time you defeat one of its forms.
Survive the attack, use your yutyrannus to buff everything and apart from that, I wish you good luck on beating it! 👍