Summary
Baldur’s Gate 3limits your party to four members, but there are a few ways to increase that number, with animal companions and elemental summons. The most morbid of these options is to make dead enemies fight for you, thanks to Animate Dead - which is more useful than its D&D counterpart.
The spell gives you four options: Zombies, Skeletons, Ghouls, and Flying Ghouls, and you can control how many you’ll create at a time with the spell’s level. They’re all fantastic options, and some will work better than others depending on the situation, but it is common for some to be more effective than others in most cases.

4Zombies
The basic zombie has mainly one advantage: They’re good damage sponges. Enemies will have an easy time hitting them, but they’re durable - at least at early levels. If your tanks are having a hard time, spreading a bunch of zombies among your enemies will be an efficient way to soak up the damage they’ll cause to your party.
Just verify they’re not super close to one another, so an area-of-effect attack won’t clean house, and they’re good to go.

Their attack bonus is a +5, and their basic damage is 2d6+3, which causes an average of 11 hit points of damage. Their main condition is called Crawling Gnaw. Essentially, if your zombie kills someone they gave this condition, the dead enemy will instantly become another zombie. This new zombie will have fewer hit points, and you can’t directly control it, but it’ll be an ally and help you out.
Undead Fortitude also helps them stay alive. The first time your zombie receives a killing blow, it’ll remain ‘alive’ in one hit point unless this killing blow is radiant damage or a critical hit. This further helps your zombies be damage sponges, staying in the fight for longer despite being killed. And, even if they die, that’s damage one of your party members didn’t receive, and that’s good.

Overall, the only weakness here is that their raw damage isn’t the best, but you can distract multiple enemies with a swarm of zombies.
3Skeletons
Skeletons offer essentially the opposite of what a zombie does. They’re ranged fighters, and though they have a better armor class, they’re not as durable, so you’ll have to protect your Skeletons instead of them protecting you. Where they shine is their damage and range.
Their attack bonus is also a +5, and their arrows cause 1d6+3 damage along with secondary damage of1d10 necrotic damage, causing an average of 13 hit points. Along with the fact they’re archers, they have an easier time hitting opponents and can position themselves in areas where they are relatively safe while attacking their enemies. They can also hit enemies your melee characters can’t reach, allowing them to focus on other opponents.

By being safer, that means they last longer through fights. And that means they’ll attack more and cause more damage overall. This distance also gives you the freedom to use area-of-effect spells without losing your own minions, and they’ll even be safe from your Turn Undead abilities since they’d also be affected by those if they’re within range.
As far as weaknesses go, they’re easier to kill as they have fewer hit points and are vulnerable to bludgeoning weapons, which don’t show up often, but it’s essential to be aware of. An enemy with a hammer or unarmed strikes can destroy a Skeleton in a single attack, so beware.

A Necromancy Wizard can summon an additional undead with any use of Animate Dead when they reach level six!
2Flying Ghoul
Ghouls, both the flying and non-flying versions, are already better melee options than zombies. Still, as the name implies, the Flying Ghoul has a lot more maneuverability on the battlefield thanks to its wings.
The fact they can fly alone makes them an effective choice. Other than that, their attack bonus is a +6, and their damage is 3d6+3, increasing their average damage to 15 hit points. Each attack also has a chance of paralyzing the enemy, which is one of the strongest conditions you can cause to an enemy, as every hit on a paralyzed enemy is a guaranteed critical hit.
They have better health and AC compared to zombies, too, and they can devour unconscious enemies, healing themselves in the process. The target has to be unconscious, whether it is from fight or asleep,so non-lethal strikesare a good option here - though it still works if the enemy is simply prone.
1Ghoul
You might be wondering why the non-flying version is ranked higher. They essentially do the same thing, but wingless, and depending on the map and how vertical it is, the Flying version might be a better option. But regular Ghouls are better tanks, keeping your characters safer.
In terms of offense, they’re exactly the same: +6 to attack, 3d6+3 to their damage, and it also has a chanceto paralyze enemies. They also feature the devour trick, recovering health in the process.
The only difference is that they trade their wings to 35 hit points and an AC of 17 instead of 30 hit points with 15 for their AC. As mentioned, it’s a slight difference, and it’s up to you which version will be better to summon during a fight. Still, the AC, in particular, can make a lot of difference if your Ghouls are soaking damage, especially from the enemy’s minions, since a Boss can hit 17 on their attacks with ease.
Essentially, they are good for putting minion versus minion, giving you breathing room to fight the main enemy easily. Still, they can paralyze their targets, so having your Ghouls gang up on the main opponent is a solid strategy.
Honorable Mention: Mummy
The Mummy is worth mentioning as a separate option outside our rank. Technically, this isn’t an option from Animate Dead but from a similar level-six spell called Create Undead.
It is by far the tankiest option, with 93 hit points and an AC of 18, but since it’s only one creature, it won’t take damage as much as three Ghouls, for example. It’s better than a single Ghoul, though, so it’s up to you which one you should use - or have both, as they use different spell levels, anyway.
They also have the ability to frighten enemies, which is a devastating condition to cause your enemies, and the Mummy can use multiple attacks on a frightened opponent, which will also make it the most aggressive option, with average damage of 23 (2d6+3 combined with 3d6 necrotic damage). Basically, it over-performs the others under the right conditions, but the lack of multiple minions makes it less attractive compared to the other summons.