Time and mana investment lands which require you to invest mana in them over a series of turns for them to function
On top of that, they give your other Legendary Creatures the ability to tap for one of any color of mana too
Nested Shambler might only make one Green Squirrel creature token when it dies, but if I were to play Yavimaya, Cradle of Growth to make all my lands Forests and enchant that Zombie with Blanchwood Armor to give it +1/+1 for each Forest I control, I could be looking at an awful lot of Squirrels
Fischer Moonfolk is a creature type
In the context of the card, it appears to be wordplay on the fact that the word "present" can refer to a gift you give to someone (in which case, it's pronounced like "pleasant") or the act of showing something off (in which case, it's pronounced like "prevent"), and the effect appears to be using both meanings at the same time
4) Ampharos has been on many of my teams having had one HGSS play through and 2 crystal play throughs meaning its been on my team 3 times