Tundras are very common and large Biomes in any Creativerse gameworld that can be found rather easily. As Tundras are typical transition regions between mild and cold climate zones, you can often find very cold snow-covered Taigas, Frozen Deserts or ice-covered Oceans directly next to Tundras, but normally Forests, Grasslands or Canyons are also close by.
If you pick up this layer of Snow then it will turn into full-sized blocks of snow in your inventory. However if you place something solid on the thin layer of Snow, like Torches or any other block, the layer of snow will vanish without leaving anything behind by making a "poof"-sound.
Tundras are useful biomes, as many Tundra Flowers will usually grow there - a necessary ingredient for Fire Resistance Potions and any kind of crafting-recipe that will accept different kinds of Flowers to be used (like Basic Health Potions for example). If you remove/pluck all Tundra Flowers from an area, then these flowers can regrow in unlit places after a longer while, however only very few of them.
Elderwood trees are common in this biome, with some Blue Flowers amongst their leaves, which are necessary to craft Blue Pigment and Flares. Blue Flowers will continue to spawn on Elderwood Leaves, even on the kind of leaves that have snow mixed in. Under these pinelike trees Rimecones can often be found, which can be used as throwing weapons.
Snowy Elderwood Leaves will turn into ordinary Elderwood Leaves without any additional snow blocks in your inventory when you harvest them. Ordinary Elderwood Leaves will not turn into snowy ones when placed into cold environments.
On Dead Grass as found in Tundras, Crisphead Lettuce can occasionally spawn and rarely even Red Mushrooms. The chances of such spawns will increase the longer you play. Also Queen Bees can sometimes spawn on Elderwood trees and later on turn into Beeswax, depending on the temperature of the environment.
While on the snow-covered parts of Tundras Blizzard Chizzards (that lay light blue eggs as pets) and sometimes Rocksters or Pebbles may roam (if Sand is close), at night aggressive Night Chizzards and many dangerous Arctic Mirus might show up.
On Dead Grass ordinary Pigsies will often spawn during the day, but also Leafies might be close to (or on) some of the trees, which means that at night Night Pigsies and Night Leafies might come out, plus occasionally maybe even a few Night Hoglets and/or Night Twiggys that are more common in Forest biomes though.
As usual for all surface-biomes, Wood Treasure Chests can spawn on any solid block in unlit areas of Tundras during the (ingame-)night, from 10:34 PM to 5:12 AM (best at nightfall and only rarely in the morning).
Beware of freezing - when walking on Snow or Ice, a freeze scale will show up and will be filled with white color as long as you stay on cold ground. As soon as this scale has completely filled up, your player-character will receive cold damage over time.
To prevent this, you can warm up easily by placing at least 3 torches onto any type of ground and standing directly on one of these torches. The freeze scale will be removed very quickly then.
Freeze Resistance Potions will reduce the freeze scale itself (the "environmental effect") nearly completely and will also reduce the cold damage over time by 50% (cut by half). Frigid Soups provide 50% cold resistance, while Frigid Sandwiches and Frigid Pies will even inverse freezing damage and turn it into an healing effect over time. All types of "Frigid" Food can be cooked in the Cooking Station with Blizzard Chizzard Eggs only provided by tamed Blizzard Chizzards.
While blocks of Ice Cap are not really any different from ordinary Ice and will also turn into plain Ice when taken, Snow Caps are special kinds of snowy blocks that cannot melt. They are able to make your freeze scale fill up more slowly than common Snow, but these blocks are rather uncommon in Tundras and much more common in Taiga as well as in snowy Mountain biomes. Snow Caps can turn into common Dirt when placed into warm environments, but not vice versa. Torches usually are not hot enough to produce this effect though.
You can melt both Snow and blocks of Ice (or Ice Caps) into Water by heating them up enough, like by placing Hardened Lava on or under it (some of which might turn into Igneous Rock when cooling down). Sometimes even pouring any kind of liquid on Snow or Ice in a large enough amount can warm these blocks up enough to melt.
However please note that Fire Bombs cannot melt blocks of Snow currently (as of R39 in February 2017), they can only melt Ice into Water. Also, if the surrounding is very cold, then units of Water as well as Corrupted Water, Mineral Water and Bog Water will freeze into blocks of Ice before long by themselves.