Goblin Electromancer

Instant and sorcery spells you cast cost {1} less to cast.

Neera, Wild Mage

Whenever you cast a spell, you may put it on the bottom of its owner's library. If you do, reveal cards from the top of your library until you reveal a nonland card. You may cast that card without paying its mana cost. Then put all revealed cards not cast this way on the bottom of your library in a random order. This ability triggers only once each turn.

From the Ashes

Destroy all nonbasic lands. For each land destroyed this way, its controller may search their library for a basic land card and put it onto the battlefield. Then each player who searched their library this way shuffles.

Teferi's Puzzle Box

At the beginning of each player's draw step, that player puts the cards in their hand on the bottom of their library in any order, then draws that many cards.

Niv-Mizzet, Parun

This spell can't be countered.
Flying
Whenever you draw a card, Niv-Mizzet deals 1 damage to any target.
Whenever a player casts an instant or sorcery spell, you draw a card.

Epitaph Golem

{2}: Put target card from your graveyard on the bottom of your library.

Junktroller

Defender
{T}: Put target card from a graveyard on the bottom of its owner's library.

Reito Lantern

{3}: Put target card from a graveyard on the bottom of its owner's library.

Ardent Dustspeaker

Whenever this creature attacks, you may put an instant or sorcery card from your graveyard on the bottom of your library. If you do, exile the top two cards of your library. You may play those cards this turn.

Tel-Jilad Stylus

{T}: Put target permanent you own on the bottom of your library.

Dutiful Knowledge Seeker

Whenever one or more cards are put into a library from anywhere, put a +1/+1 counter on this creature.
{3}: Put target card from a graveyard on the bottom of its owner's library.

Fblthp, Lost on the Range

Ward {2}
You may look at the top card of your library any time.
The top card of your library has plot. The plot cost is equal to its mana cost.
You may plot nonland cards from the top of your library.

Tomb Trawler

Conjurer's Bauble

{T}, Sacrifice this artifact: Put up to one target card from your graveyard on the bottom of your library. Draw a card.

Have

River Song

Meet in Reverse — You draw cards from the bottom of your library rather than the top.
Spoilers — Whenever an opponent scries, surveils, or searches their library, put a +1/+1 counter on River Song. Then River Song deals damage to that player equal to its power.

Barkform Harvester

Changeling (This card is every creature type.)
Reach
{2}: Put target card from your graveyard on the bottom of your library.