Here is the full list of all 30 Undertale trophies - there are 14 bronze, 10 silver, 5 gold and 1 platinum.
Obtain all other Undertale trophies.
Reach the second save point in the CORE.
Donate 350G to the Dog Shrine.
Donate 280G to the Dog Shrine.
Donate 230G to the Dog Shrine.
Reach Hotland 3F.
Reach Hotland 2F.
Enter Hotland.
Donate 190G to the Dog Shrine.
Donate 155G to the Dog Shrine.
Donate 125G to the Dog Shrine.
Donate 100G to the Dog Shrine.
Donate 78G to the Dog Shrine.
Get two items.
Reach the place where it rains.
Arrive at Waterfall.
Donate 59G to the Dog Shrine.
Donate 43G to the Dog Shrine.
Donate 30G to the Dog Shrine.
Donate 20G to the Dog Shrine.
Donate 12G to the Dog Shrine.
Donate 6G to the Dog Shrine.
Donate 2G to the Dog Shrine.
Get to the Spaghetti save point in Snowdin.
Arrive at Snowdin.
Reach the mouse hole in the Ruins.
Get four items.
Get three items.
Get an item.
Enter the Ruins.