So Warhammer Fantasy doesn't have a bug race, but Tyranids seem like they would be a perfect fit. One of the first things that needs to be nailed down are the slots and unit types that they translate in to. I would ask for your help in finalizing the final result on this first step:
Unit Name 40K Slot 40K Type FB Slot FB Type Hive Tyrant HQ MC Lord Monster Trygon Prim Heavy MC Lord Monster Tervigon HQ MC Hero Monster Tyranid Prime HQ Inf Hero Monstrous Infantry Broodlord Troop Inf Hero Infantry Zoanthrope Elite Inf Hero? Infantry Warrior Troop Inf Core Monstrous Infantry Genestealer Troop Inf Core Infantry Termagant Troop Inf Core Infantry Hormagaunt Troop Inf Core Infantry Ripper Swarm Troop Inf Core Swarm Hive Guard Elite Inf Special Monstrous Infantry Venomthrope Elite Inf Special Monstrous Infantry? Lictor Elite Inf Special Monstrous Infantry? Pyrovore Elite Inf Special Monstrous Beast Ravener Elite Beast Special Monstrous Beast Sky-slasher Fast Jump Inf Special Swarm Gargoyle Fast Jump Inf Special Infantry Carnifex Heavy MC Special Monster Biovore Heavy Inf Special Monstrous Beast Haruspex Elite MC Rare Monster Shrike Fast Jump Inf Rare Monstrous Infantry Harpy Fast FMC Rare Monster Hive Crone Fast FMC Rare Monster Trygon Heavy MC Rare Monster Mawloc Heavy MC Rare Monster Exocrine Heavy MC Rare Monster Tyrannofex Heavy MC Rare Monster Tyrant Guard HQ Inf Rare Monstrous Infantry
So, thoughts on adjustments? It's a huge list, I know, and some trimmings may need to come in to play here and there, but this is the starting point to work with.