All pet granting items and constellations

Nature's Call Regalia - Mythical Beastcaller's set
+1 Summon Limit to Summon Briarthorn
https://www.grimtools.com/db/itemsets/44

Mythical Will of Bysmiel
+1 Summon Limit to Summon Familiar
https://www.grimtools.com/db/items/8986

Shepherd of Lost Souls
+1 Summon Limit to Summon Hellhound
https://www.grimtools.com/db/itemsets/108

Warden's Judgement mace
https://www.grimtools.com/db/items/8422
+1 Summon Limit to Raise Skeletons

Mythical Veilpiercer dagger
https://www.grimtools.com/db/items/8530
+1 Summon Limit to Raise Skeletons

Mythical Guardian of Death's Gates two-handed axe
https://www.grimtools.com/db/items/8801
+2 Summon Limit to Raise Skeletons

Mythical Black Grimoire of Og'Napesh
https://www.grimtools.com/db/items/9346
Summon Revenant of Og'Napesh (Channel the dark writings of Og'Napesh to summon his most foul revenant back into the world of the living)

Mythical Blightshard Amulet
https://www.grimtools.com/db/items/8974
Summon Blighted Rift Scourge (Summon a Blighted Rift Scourge from the depths to follow your every command)

Mythical Heart of the Mountain
https://www.grimtools.com/db/items/9008
Summon Chillmane (Calls forth a mighty Chillmane Yeti to fight beside you)

Hysteria relic
https://www.grimtools.com/db/items/8213
Summon Crab Spirit (Bind a spirit of a swamp creature to serve you. The spirit chills foes with its icy attacks)

Savage relic
https://www.grimtools.com/db/items/1486
Summon Stormhound (Call forth a loyal Stormhound, an eldritch beast born of the heavens.)

Dirge of Arkovia
https://www.grimtools.com/db/items/8218
Summon Skeletal Servant (Bind the remains of a hundred tormented souls to serve you. This terrifying being cleaves through foes and traps them within cages of bone.)

Diviner's Vision
https://www.grimtools.com/db/itemsets/123
+ 1 Summon Limit to Reap Spirit

Mythical Bonescavenger's Deathgrips
https://www.grimtools.com/db/items/9113
Raise Spirit (Use the energy of a recent kill to call forth a tormented spirit to aid you.)
+1 Summon , 3 Summon Limit

Mythical Black Hand of Sanar'Siin
https://www.grimtools.com/db/items/9288
Conjure Devourer (Pull a Chthonian Devourer from the depths of the void to protect you)
+1 Summon, 3 Summon Limit

Salazar's Sovereign Blade
https://www.grimtools.com/db/items/2742
Call Forth the Harbinger (Conjures Salazar's Harbinger from the depths of the void)

Mythical Black Scourge
https://www.grimtools.com/db/items/9319
Conjure Black Scourge (Your wanton slaughter calls to the void.)
+1 Summon, 3 Summon Limit

Karvor's Conjuring Bone
https://www.grimtools.com/db/items/7171
Reckless Guardian (Calls forth a guardian with strong attacks.)

"of Binding" off-hand suffix
https://www.grimtools.com/db/suffixes/6637
Reckless Guardian (Calls forth a guardian with strong attacks.)

Marrow Band
https://www.grimtools.com/db/items/960
Stalwart Guardian (Calls forth a guardian with strong defenses and high threat.)

Keeper's suffix
https://www.grimtools.com/db/prefixes/4356
Stalwart Guardian (Calls forth a guardian with strong defenses and high threat.)

Will of Bysmiel
https://www.grimtools.com/db/items/896
Invocation to Chaos (Call out to the void and summon vile fiends to fight for you until such a time as the void calls for them to return.)

Primal Instinct
https://www.grimtools.com/db/items/1509
Swarm Mind(The rhythmic pace of your never-ending strife calls forth a Swarmling to your aid.)
+1 Summon, 5 Summon Limit

Soul of Lord Nazaran - The Blood Knight set
https://www.grimtools.com/db/itemsets/140
Soul of Nazaran (Summon the tormented soul of Lord Nazaran to lash out at your foes and transfer the agony it inflicts as life essence for you.)

Nemesis - Nemesis relic
https://www.grimtools.com/db/items/1497
Summon Nemesis (Call forth Nemesis, demigod of the shadows and lord of the night hunt.)

Deathstalker - Deathstalker relic
https://www.grimtools.com/db/items/11374
Summon Deathstalker (Call forth Deathstalker, a fearsome embodiment of Mogdrogen's fury that shreds the Physical, Poison and Bleed Resistance of nearby enemies.)

Stormtrap scepter
https://www.grimtools.com/db/items/2122
Wind Devil, 3 Summon Limit (Shamans were often called upon to bring rain in times of heavy drought. This ritual has been manipulated by clever Stormcallers to conjure a swirling wind devil that lifts rocks and debris into the air, battering foes and ravaging them with the harsh power of the elements)

Mythical Trozan's Starkeeper scepter - Trozan's Skybreach
https://www.grimtools.com/db/items/9334
+ 1 Summon Limit to Wind Devil

Yeti Horn off-hand
https://www.grimtools.com/db/items/2216
+ 1 Summon Limit to Wind Devil

Bloodbathed Servants - Blood Knight's Pendant
https://www.grimtools.com/db/items/11380
Call Upon the Bloodbathed, +1 Summon, 4 Summon Limit (Call forth a bloodied servant of Nazaran to cast vitality-sapping spells upon your foes before the torment of the grave calls upon it once more.)

Wrath of Agrivix set
https://www.grimtools.com/db/itemsets/65
Agrivix's Pact +1 Summon, 3 Summon Limit (Conjure a wisp of arcane energy to assault your foes.)

Cindertouch gloves
https://www.grimtools.com/db/items/8045
Cinderwind , +1 Summon, 3 Summon Limit (Conjure a blaze of living flame to incinerate your foes.)

Quillthrower of Dreeg two-handed crossbow
https://www.grimtools.com/db/items/9399
Eye of the Guardian, +1 Summon, 3 Summon Limit (Conjure one of the infinite eyes of Dreeg to protect you with a barrage of spines)

Black Gem of Dreeg amulet
https://www.grimtools.com/db/items/9003
Gaze of Dreeg, +3 Summon, 6 Summon Limit (Unleash a trio of haunting eyes of Dreeg to track down your foes before exploding in a burst of bile and venom.)

Unknown Soldier constellation
http://grimdawn.wikia.com/wiki/Unknown_Soldier
Living Shadows (A manifestation of a nameless hero rises to fight alongside you.)

Revenant constellation
http://grimdawn.wikia.com/wiki/Revenant
Raise the dead , 3 summon limit (Raise the dead to serve you. The necrotic energies required for this ritual are very unstable however, and the undead minions will only exist for a limited time.)

Bysmiel's Bonds
http://grimdawn.wikia.com/wiki/Bysmiel%27s_Bonds
Bysmiel's Command (Call forth an eldritch hound to snap and tear at your foes. The hound's presence in the physical realm is unstable and it will only remain at your side for a limited time.)