Brought over from:
https://www.curseforge.com/minecraft/mc-mods/more-trophies-massive-trophies?comment=16

For what I found, it appears it affects all the spider variants and some ghasts (Queen Ghast) from Special Mobs and the Cougar from Wild Mobs
I will try and compile a list of all the affected mob trophies I can find

edit: Here's a list of all the affected mobs:

Special Mobs Mod:
Ghast Variants: Queen Ghast / King Ghast / Baby Ghast / Faint Ghast / Unholy Ghast / Mini Ghast
Skeleton Variants: Giant Skeleton / Spitfire Skeleton
Spider Variants: Hungry Spider / Mother Spider / Giant Spider / Baby Spider / Desert Spider / Small Spider / Tough Spider
Cave Spider Variants: Mother Cave Spider / Web Cave Spider / Witch Cave Spider / Baby Cave Spider / Tough Cave Spider / Flying Cave Spider

Blaze Variants: Wildfire / Cinder
Enderman Variants: Mini Enderman
Zombie Variants: Giant Zombie
Silverfish Variants: Fishing Silverfish / Tough Silverfish
Creeper Variants: Mini Creeper
Pigmen Variants: Giant Zombie Pigman

There are also two trophies related to Special Mobs that are unobtainable as per my testing, which are an entity trophy related to the spiders' spitball attack and something called entity.zombdarkcreeperie which I cannot find anything about. There is also a duplicated version of the regular cave spider trophy which is broken like these others and actually overrides ObsTrophies' own working cave spider trophy.

Wild Mobs:

Cougar
There is also a trophy for a "druid" but I couldn't find a mob with that name or without trophy for Wild Mobs. The trophy had its name displayed as entity.wildmobsdruid or similar, it was how I found this trophy was for Wild Mobs.

Ender Zoo's Fallen Steed trophy is also bugged (which Obstrophies supposedly didn't add acording to their mod page)

There is a trophy for a mob called "Wizard" but I don't know to which mod that belongs since I couldn't find a mob named Wizard in my game.

This mod also adds trophies for the Primitive Mobs Mod despite it never being mentioned anywhere.