Just like the most powerful cards in other card games, Skullclamp is deceptively simple
it could be a general reanimator commander as this is an extremely cheap, repeatable reanimation spell and cards like Valgavoth, Terror Eater are worth three random rats, but it begs the question: Where are the rats coming from
It costing ten mana can be looked at as an upside actually as here are some of the dumb spells you can cheat into play, like Maelstrom Wanderer, Call Forth the Tempest, Emergent Ultimatum, Eerie Ultimatum, and Last March of the Ents
Permanents with indestructible aren't destroyed this way
A recent example of this is the Dracula box topper packs from Crimson Vow
The trippy part about this card is the Mine Excavation riff