Trading your creature in combat is when, through attacking and blocking, one creature dies and causes another creature to die
You could even set things up where Sin resurrects a missing combo piece this way
From what I understand, Disney wanted to steer clear of that association in the initial release, especially as many children could/would be attending prereleases
Alpha s Grizzly Bears was the first card with the creature type, and it also gave us the slang name of bears for the low-mana 2/2 creature found in many MTG sets, often a creature with no abilities (vanilla) back when those were more common
While the base-rarity version is extremely affordable at less than $1, the QCSR version has been worth double digits for most of its lifetime
How you rest is a window into what drives you when no one's watching