The headline: SAR pulls land at roughly 1-in-3 boxes, while MUR sits at a brutal 1-in-50
You can use it in decks like Dragapult ex to get attacks off more reliably, or use it to bypass the need to include entire energy types in your deck list
This means when you hit someone for combat damage with this squirrel, they gain 2 poison counters
Since Fetch Lands need to sacrifice as part of their cost to find lands that actually tap for mana, these will ensure that theres always a land for Carmen to find with her attack trigger, and will continually grow Carmen, giving her access to larger cards in your graveyard
The first time I read his flavour text, I burst out laughing
Think of the Base Set Holo Charizard, which was the showpiece of schoolyards