My main idea behind this hero is that it has 2 states, much like the Queen of Thorns or Torchbearer, however, it is not simply a case of switching between them.
The general idea is that the insect starts out as a larvae with weak offense but strong defense. At level 4, the Dire Waspe gains the ability to inject an enemy player with an egg, dealing high damage over time, but gradually slowing the enemy to a halt after 15 seconds. At which point, the Dire Wasp true form emerges as a nightmarish wasp-like creature with massive offensive damage but weaker defensive capability. The Dire Wasp will revert back to its Larval state if the player dies, or if the player chooses to do so.
Demigod Type:
Assassin
Larval State:
The Dire Wasp would start in a Larval state, with a ranged spitting attack and + 25% armor bonus but - 25% attack damage.
Appearance:
In the larval state, the Dire Wasp would resemble a massive earth-coloured maggot or caterpillar with hardened scales and spines, leaving a slimey trail in its wake.
Larval Abilities:
Poisoned Spines: Passive. Deals 25/50/75/100% return damage to any units that attack the Dire Wasp in melee combat while in Larval form.
Toughened Carapace: Passive. Increases Armor in Larval form by (placeholder values) 300/700/1100/1500
Corrosive Bile: 1 second cast, long ranged. Ranged attack which reduces the targets hp regeneration by 10/20/30/40 for 15 seconds and deals 250/500/750 damage over that time.
Infest: medium ranged. instant cast. Injects an enemy player with the wasps egg and leaves behind an empty shell. Silences the enemy whilst dealing 500/1000/1500 damage over 15 seconds and gradually slows them to a halt, during this time the Dire Wasp cannot move or attack but can see the infected players movements. Once the effect ends, the Dire Wasp will burst out of the infected player as a giant wasp with full hp and mana & all new abilities.
Wasp State:
In its wasp state, the Dire Wasp has a melee attack with its stinger and gains +25% attack damage, but looses 25% armor.
Appearance:
Something like this!

Abilities:
Corrosive Bile: See Larval form description above.
Poison Stinger: A short range instant attack which stuns a targetted enemy for 2/3/4/5 seconds and deals 400/600/800/1000 damage.
Wings of Evil: Passively increases movement speed and attack speed by 10/20/30/40%
Wicked Venom: Passive. All attacks deal an additional 100/200/300/400 damage over 10 seconds and reduce the targets armor by 200/400/600/800. Does not stack.
Cocoon: 1 second cast. The Dire Wasp turns into a cocoon and is invulnerable but unable to move for 5 seconds, once this effect ends the Dire Wasp will revert back into larval form, and will be unable to cast the Infest ability for 100 seconds.
Playstyle:
As you can imagine, this character would require some careful balancing to ensure it doesn't become massively overpowered, as it is a double edged sword of offensive power and defensive stength.
Harassment and some tanking would be the name of the game early on, waiting for the perfect time to strike with Infest, then unleashing a cavalcade of fast moving, fast hitting damage on the enemy in wasp mode, but risking it all in the process.
Hope you like the idea, and more so, that SD implement it one day.