Question about final bosses

[Seb]

I think I've defeated all of the final bosses but correct me if I'm wrong.
I read on the wiki that the final bosses are:
-Mom's Foot
-Mom's Heart
-IT LIVES!!
-Hush
-Satan
-Ultra Greed
-Delirium

I've managed to clear the void floor completely and all bosses but I'm not sure what would be the next chapter would be or how to get there.

[Nazemec]

You're missing a few: ???, the Lamb, Mega Satan, and eventually Ultra Greedier. Details on how to get to them below in the spoilers.

???: Boss of the Chest. Kill Isaac 5 times to unlock the Polaroid (dropped by Mom), then take it and kill Isaac during a run. The run won't end here, you'll be sent to the Chest floor instead.
The Lamb: Boss of the Dark Room. Kill Satan 5 times to unlock the Negative (dropped by Mom), then take it and kill Satan during a run. The run won't end here, you'll be sent to the Dark Room floor instead.
Mega Satan: Once you've killed either ??? or the Lamb once, you'll see a giant door in the starting room of both the Chest and the Dark Room. To open it, you need a special key. You'll have to kill two Angels during a single run to get both halves, either by "donating" enough blood in a Sacrifice room or by bombing angel statues in Angel Deal rooms. You could also open the giant door with Mr Me! or Dad's Key (both active items), or the Get Out Of Jail card, but the Angels' key is the "legit" way, so to speak.
Ultra Greedier: Variant of Ultra Greed, this is the boss of Greedier mode (hard Greed mode). To unlock it, put 500 coins into the Greed machine (the one at the end of Greed mode, not the one in shops).



If you refer to completion marks (the symbols you can see when selecting a character), Mom doesn't have one, the Heart and it Lives have the same one (since they're both considered as the same boss by the game, It Lives is just a variant), and don't forget the Boss Rush (kill Mom under 20 minutes to access it). All other "end bosses" (both the ones you listed and the ones you're missing) have their own mark as well, leading to a total of 10 for each character.
By the way, considering your question, you're most likely missing some characters as well. The total (as of today) should be 15.

Edits:
Messed up some "spoiler" tags. Fixed them.

[Seb]

I must of mean't Mega Satan because I have killed him a few times. I have the ??? character but I don't remember fighting him. Ultra Greedier should be fun to try and beat though!

[Seb]

I have 4 endings that I haven't unlocked

[Nazemec]

Originally posted by Seb:

I have 4 endings that I haven't unlocked

Without their numbers, this information doesn't really mean much. :P
You can compare your endings list with the wiki if you prefer.
https://bindingofisaacrebirth.gamepedia.com/Endings

Originally posted by Seb:

I must of mean't Mega Satan because I have killed him a few times.

To be sure: if you've beaten him in a regular boss room on Sheol (a rather dark floor right after the Womb), then it's just Satan, not Mega Satan.

[Seb]

Originally posted by Nazemec:

Originally posted by Seb:

I have 4 endings that I haven't unlocked

Without their numbers, this information doesn't really mean much. :P
You can compare your endings list with the wiki if you prefer.
https://bindingofisaacrebirth.gamepedia.com/Endings

Originally posted by Seb:

I must of mean't Mega Satan because I have killed him a few times.

To be sure: if you've beaten him in a regular boss room on Sheol (a rather dark floor right after the Womb), then it's just Satan, not Mega Satan.

I'll check after this run I'm on rn, I just defeated The Lamb and gonna try my first Victory Lap (:
The Satan that I have killed before was the one that transforms into multiple versions ending with his legs coming down to step on you.

[Nazemec]

Originally posted by Seb:

The Satan that I have killed before was the one that transforms into multiple versions ending with his legs coming down to step on you.

That's the normal one, boss of Sheol. First phase is the Fallen, then Satan, then Satan's hooves. :P

[Seb]

Originally posted by Nazemec:

Originally posted by Seb:

The Satan that I have killed before was the one that transforms into multiple versions ending with his legs coming down to step on you.

That's the normal one, boss of Sheol. First phase is the Fallen, then Satan, then Satan's hooves. :P

I just finished the run by jumping into the golden chest that isaac drops. My save game file 1 now says "The End"

[Nazemec]

Originally posted by Seb:

Originally posted by Nazemec:

That's the normal one, boss of Sheol. First phase is the Fallen, then Satan, then Satan's hooves. :P

I just finished the run by jumping into the golden chest that isaac drops. My save game file 1 now says "The End"

Don't pay too much attention to the save file image.

[Seb]

JUST DEFEATED MEGA SATAN!