Monster Hunter World: Iceborne - Iceborne Monsters

There is a lot of content here. Let me list them by size and some other aspects. You can find their info at Ecological Research in your camp. Max research level of each and every one of those is Lv. 4.

If you aim for golden crowns, I suggest raising your Guilding Lands to level 6-7, then you can fight tempered versions of monster specific to that area, which are mostly close to the crown you want. It's still RNG based, but at least it's easier to farm them. Another great way is to play tempered investigations and investigations that have at least some silver and gold rewards. The harder the better.

Large Monsters

Beotodus
Variant: No

Banbaro
Variant: No

Large Crown

Viper Tobi-Kadachi
Variant: Yes

Nightshade Paolumu
Variant: Yes

Coral Pukei-Pukei
Variant: Yes

Barioth
Variant: No

Nargacuga
Variant: No

Glavenus
Variant: No

Tigrex
Variant: No

Small Crown

Brachydios
Variant: No

Shrieking Legiana
Variant: Yes

Fulgur Anjanath
Variant: Yes

Acidic Glavenus
Variant: Yes

Ebony Odogaron
Variant: Yes

Velkhana
Variant: No

Seething Bazelgeuse
Variant: Yes

Blackveil Vaal Hazak
Variant: Yes

Namielle
Variant: No

Savage Deviljho
Variant: Yes

Small Crown

Ruiner Nergigante
Variant: Yes

Shara Ishvalda
Variant: No

Zinogre
Variant: No

Large Crown

Yian Garuga
Variant: No

Small Crown

Scarred Yian Garuga
Variant: Yes

Brute Tigrex
Variant: Yes

Gold Rathian
Variant: Yes

Silver Rathalos
Variant: Yes