Alot of players asked me to make a "guide" for the fusing pets, so i decided to make one real quick.       Shadow pet    
Fuse cost: x3 death pets, x3 mini-me pets, and 350 blood shards. Shadow figure of your character. Combined effects of the mini-me and death pet (1+ Item kept on death + absords 10% damage.)         Infernal Yoshi    
Fusion cost: x2 yoshi pets, x1 phoenix pets, x250 blood shards Combined effect of the yoshi and blood phoenix pets. (Banks untradeable loots & +15% range bonus)           Celestial Yoshi    
Costs x3 yoshis, x2 aliens, and x250 blood shards. Gives a unique shiny cosmetic variant. Combines the effect of the yoshi and alien pet. (Banks untradeable loots & teleport out of any wilderness. NOTE* EXCEPT IF YOU ARE TELEBLOCKED!)           Holy Berserker Pet     Fusion cost: x3 prayer spirit pets, x2 blood berserker pets, and x300 blood shards. Combined effect of prayer spirit pet and blood berserker pet. Includes unique ability: 1/6 of damage dealt is removed from your opponent's prayer. Stacks with smite and soulsplit.           Giant Wolpertinger Pet    
Fusion cost: x2 phoenix x2 blood lord x2 wolpertinger. Combined Effect of wolpertinger, blood lord and phoenix. (+7 magic boost every 10 seconds & 15% Range bonus)     Nocturnal Yoshi    
Fusion cost: x3 yoshi pets, x2 death pets & x150 blood shards.
Combined effect of yoshi and death pet   (automatically sends unspawnables to your bank + u keep 1 extra item.     Fortune Genie     Costs: x3 genie pets, x2 treasure fairies, x150 blood shards
Genie pet with a glowing cosmetic effect (Has a 35% chance for rare drops to be double dropped)
Includes bonuses of fused pets (x2 exp, and 15% drop rate increase)