Combos Utilizing Symbiotic-Beast

play recurring nightmare and sac a creature to bring in your symbiotic beast from the graveyard, sac the beast to the altar for mana and you have four mana to do the process over leaving one left over, keep repeating and you have infinite mana

Play Gleancrawler and then equip with Whispersilk Cloak, Thoughtpicker Witch can be replaced with any creature that has sacrifice capabilities. If you do go with this combo, Symbiotic Beast can be replaced with Symbiotic Elf/Wurm or any creature with a death benefit. Get said creature back at the end of turn and repeat. I'd get a creature that gives you a life bonus when sacrificed, or add in Savra, Queen of Golgari.

play both beasts and the change aether charge to insects so when the beasts die 16 damage to opponents

get a lot of little 1/1's

sacrifice the beast and then the insect tokens to make pb a 7/7

get all the symbiotic creatures you can into play, then obliterate the entire table and attack with your army of 1/1 insect tokens, devastate your opponent and gain 1 life for each token that attacks.

hav nantuko husk sacrafice Symbiotic beast,u get 4 tokens, ur opponent has to sacrafice a creature, have Nighteyes the Desecrator bring Symbiotic beast back

sac the symbiotics to husk and get 'em back next upkeep

clear the board and get a bunch of 1/1s!