Its a Touhou DotA, Called Defense of the Shrines. The 'Alpaca' Sells the 'Llama' recipes, which increase movement speed and a stat.
The yukkuris are actually used to bring items to your hero, if you're too busy/lazy to go back to base to buy them. The larger ones are 'upgraded' ones that can teleport, and temporarily turn invulnerable.
Yup. But I know, some people (for example my brother) uses Yukkuri to fight. O_o Koyukkuri has 100 HP and can't attack. Big yukkuri has 300 HP, can attack (20-20 dmg) and has skills written by maximusfive. I tried to 'tune' a yukkuri with items, and i ended with Yukkureimu stats: over 115 dmg and 800 hp