Monarch of Spiders

some of them could even be described as the Monarchs of Spiders. you get the following benefits:

• You learn the Conjure Animals spell but you can only summon "Swarm of Insects (Spiders)" and the Dominate Beast spell but you can target only spiders (you can ignore "Swarm of Insects (Spiders)" Immunity against Charmed if you cast this spell on it). You can cast each of these spells without expending a spell slot. Once you cast either of these spells in this way, you can’t cast that spell in this way again until you finish a long rest. Wisdom is your spellcasting ability for these spells.