Minecraft wiki entry for Gathering_resources_on_peaceful_difficulty, associated text: Magma Cream can either be obtained as a drop from magma cubes, by crafting a slimeball and a blaze powder, or by looting bastion remnant chests. In peaceful, the only way to obtain Magma Cream is by looting bastion remnant chests. However, magma creams are almost practically useless in peaceful mode, as their only use is to craft magma blocks, while those can be commonly found within the nether. It can't be used as a brewing ingredient, as blaze powder and blaze rods are unobtainable.