Moose Calf
Moose Calf has 1,000 health.
It takes extra damage from fire; it resists blunt, slash and frost; spirit does nothing to it at all. Pierce lands at full damage, so that is what to bring.
Its hardest hit is horns at 160 slash, out of 2 attacks.
Of everything craftable, 
Thunderblood Crossbow, 
Lightning Strike and 
Frostfire Crossbow put the most damage through what it resists.
Moose Calf is the young of a bred 
moose pair, and not the reduced thing the name suggests: it carries the adult's full 1,000 health at the same 12.6 run speed. It has the 160 slash gore and the 150 blunt kick, but not the adult's 145 slash antler sweep. It drops nothing at all when killed, no meat, hide or sinew, so the only use for one is growing it into an adult.
There is no reason to kill one. It hits as hard as its mother, gives no meat, no hide and no sinew, and killing it costs you a future tame. Leave it and take the adult, or pen the pair.
With devcommands enabled, this spawns Moose Calf in front of you. The third number is the level: 3 spawns a 2-star.
Creature ID: Moose_calf · all console commands and IDs